Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Dermal absorption and toxicological risk assessment : pitfalls and promises
    Buist, H. - \ 2016
    Wageningen University. Promotor(en): Ruud Woutersen; Ivonne Rietjens, co-promotor(en): J.J.M. van de Sandt. - Wageningen : Wageningen University - ISBN 9789462577275 - 200
    skin - absorption - permeability - in vitro - experiments - exposure assessment - risk assessment - toxicology - biocides - rodenticides - preservatives - disinfection - huid - absorptie - permeabiliteit - in vitro - experimenten - blootstellingsbepaling - risicoschatting - toxicologie - biociden - rodenticiden - conserveermiddelen - desinfectie

    Absorption of toxic substances via the skin is an important phenomenon in the assessment of the risk of exposure to these substances. People are exposed to a variety of substances and products via the skin, either directly or indirectly, while at work, at home or in public space. Pesticides, organic solvents and metalworking fluids are seen to be important contributors to adverse health effects due to occupational exposure via the skin. In daily life, cosmetics, clothing and household products are the most relevant commodities with respect to exposure via the skin.

    Given the importance of skin exposure in the assessment of the risk of toxic substances, the objective of this thesis was to further develop, evaluate and improve methods for including skin absorption data this assessment.

    In this thesis, four factors influencing dermal absorption, namely dermal loading (chapters 3 and 6), irritative/corrosive potential (chapters 3 and 4), frequency of exposure (chapters 3, 4 and 5) and the vehicle used (chapter 5), were investigated in more detail. Furthermore, a model to extrapolate infinite dose absorption data to finite dose conditions, baptized Dermal Absorption Model for Extrapolation (DAME), was developed and tested.

    I

    n chapter 2 of this thesis, the relationship between relative dermal absorption and dermal loading was investigated. Hundred-and-thirty-eight dermal publicly available absorption experiments with 98 substances were evaluated. The results obtained revealed that dermal loading ranged mostly between 0.001 and 10 mg/cm2. In 87 experiments (63%), an inverse relationship was observed between relative dermal absorption and dermal loading. On average, relative absorption at high dermal loading was 33 times lower than at low dermal loading. Known skin irritating and volatile substances less frequently showed an inverse relationship between dermal loading and relative absorption. It was concluded that when using relative dermal absorption in regulatory risk assessment, its value should be determined at or extrapolated to dermal loadings relevant for the exposure conditions being evaluated.

    I

    n chapter 3 of this thesis, a literature search was presented with the aim to investigate whether neglecting the effects of repeated exposure may lead to an incorrect estimate of dermal absorption. The results demonstrated that the effect of repeated versus single exposure does not demonstrate a unique trend. Nevertheless, an increase in daily absorption was frequently observed upon repeated daily exposure. The little information available mostly concerned pharmaceuticals. However, consumers and workers may be repeatedly exposed to other types of chemicals, like disinfectants and cleaning products, which often contain biocidal active substances that may decrease the barrier function of the skin, especially after repeated exposure. These biocidal products, therefore, may present a safety risk that is not covered by the current risk assessment practice since absorption data are usually obtained by single exposure experiments. Consequently, it was decided to investigate the importance of this issue for biocide safety evaluation. As the literature search revealed that hardly any data on absorption upon repeated dermal exposure to biocides are available, it was concluded that data need to be generated by testing.

    To cover the entire range of biocidal products in such testing, a representative series of biocidal substances should be tested, making in vitro testing of dermal absorption the preferred choice over in vivo testing. Based on an inventory made, it appeared that the 16 product types represented among the biocidal products authorised in the Netherlands could be clustered into 6 more or less homogeneous categories based on similarity in active substances. This result could facilitate experimental testing by providing a basis for selection of a limited number of representative compounds to be evaluated.

    I

    n chapter 4 of this thesis, the importance of the effect of repeated dermal exposure on skin permeability for biocide safety evaluation was investigated, using a selection of nine representative biocides from the inventory made in chapter 3. The in vitro dermal penetration of tritiated water and [14C]propoxur was chosen as a measure of the permeability and integrity of human abdominal skin after single and repeated exposure. The results indicated that single and repeated exposure to specific biocidal products (e.g. the quaternary ammonium chlorides DDAC and ADBAC) may significantly increase skin permeability, especially when the compounds are applied at high concentrations, while a substance like formaldehyde may reduce skin permeability under specific conditions.

    I

    n chapter 5 of this thesis, the in vitro dermal absorption kinetics of the quaternary ammonium compound didecyldimethylammonium chloride (DDAC) during single and repeated exposure was studied in more detail. In addition, the influence of biocidal formulations on the absorption of DDAC was investigated, because it was expected that formulation characteristics may be another factor influencing its dermal absorption. The analysis of biocidal products on the Dutch market, reported in chapter 3, indicated that DDAC is often used in combination with other active ingredients. DDAC was most frequently combined with formaldehyde, glutaraldehyde and/or alkyldimethylbenzyl­ammo­nium chloride (ADBAC). Consequently, commercial formulations containing one or more of these additional active ingredients were selected, in addition to one formulation containing only DDAC as an active ingredient. The selected commercial formulations tended to reduce skin penetration of DDAC. This was most pronounced with the formulation containing the highest concentration of formaldehyde (196 mg/mL) and glutaraldehyde (106 mg/mL), which reduced the flux of DDAC across the skin by 95%. The reduction caused by the only tested formulation containing no other active ingredients than DDAC, and thus incorporating no aldehydes, was smallest, and did not reach statistical significance.

    I

    n chapter 6 of this thesis, a simple in silico model to predict finite dose dermal absorption from infinite dose data (kp and lag time) and the stratum corneum/water partition coefficient (KSC,W) was developed. This model was tentatively called Dermal Absorption Model for Extrapolation (DAME). As dermal exposure may occur under a large variety of conditions leading to quite different rates of absorption, such a predictive model using simple experimental or physicochemical inputs provides a cost-effective means to estimate dermal absorption under different conditions.

    To evaluate the DAME, a series of in vitro dermal absorption experiments was performed under both infinite and finite dose conditions using a variety of different substances. The kp’s and lag times determined in the infinite dose experiments were entered into DAME to predict relative dermal absorption value under finite dose conditions. For six substances, the predicted relative dermal absorption under finite dose conditions was not statistically different from the measured value. For all other substances, measured absorption was overpredicted by DAME, but most of the overpredicted values were still lower than 100%, the European default absorption value for the tested compounds.

    In conclusion, our finite dose prediction model (DAME) provides a useful and cost-effective estimate of in vitro dermal absorption, to be used in risk assessment for non-volatile substances dissolved in water at non-irritating concentrations.

    I

    n chapter 7 of this thesis, the results of the research reported in chapters 2 to 6 were put into perspective, the pitfalls and promises emanating from them discussed and general conclusions drawn. The possible influence of vehicles on absorption and the possible impact of irritative or corrosive vehicles or chemicals on the skin barrier have been demonstrated in this thesis. An in silico predictive model tentatively called DAME was developed, which enables the user to evaluate a variety of dermal exposure scenarios with limited experimental data (kp and lag time) and easy to obtain physicochemical properties (MW and log KOW). The predictions of our experiments reported in chapter 6 were compared to those of the Finite Dose Skin Permeation (FDSP) model published on the internet by the US Centers for Disease Control and Prevention (CDC). DAME outperformed FDSP (R2 of the correlation predicted/measured potential absorption 0.64 and 0.12, respectively). At present, the applicability domain of DAME is limited to non-volatile substances dissolved in aqueous solvents. However, in future the model will be adapted to include volatile substances as well.

    Altogether, it is concluded that dermal exposure can be an important factor in risks posed by chemicals and should be taken into account in risk assessment. The methods to actually do this are still open for further improvement to better account for the various factors influencing skin penetration and to develop adequate combinations of in vitro and in silico models that can accurately predict human dermal absorption.

    Oligosaccharides in Urine, Blood, and Feces of Piglets Fed Milk Replacer Containing Galacto-oligosaccharides
    Difilippo, Elisabetta ; Bettonvil, Monique ; Willems, Rianne ; Braber, Saskia ; Fink-Gremmels, Johanna ; Jeurink, Prescilla V. ; Schoterman, Margriet H.C. ; Gruppen, Harry ; Schols, Henk A. - \ 2015
    Journal of Agricultural and Food Chemistry 63 (2015)50. - ISSN 0021-8561 - p. 10862 - 10872.
    absorption - capillary electrophoresis - creatinine - fermentation - GOS - intestine - liquid chromatography - mass spectrometry - pig - prebiotics

    Human milk oligosaccharides (HMOs) are absorbed into the blood (about 1% of the HMO intake) and subsequently excreted in urine, where they may protect the infant from pathogen infection. As dietary galacto-oligosaccharides (GOS) have partial structural similarities with HMOs, this study investigated the presence of GOS and oligosaccharides originating from milk replacer in blood serum, urine, and cecal and fecal samples of piglets, as a model for human infants. Using liquid chromatography-mass spectrometry and capillary electrophoresis with fluorescence detection, oligosaccharides originating from piglet diet including 3′-sialyllactose and specific GOS ranging from degree of polymerization 3 to 6 were detected in blood serum and in urine of piglets. In blood serum, GOS levels ranged from 16 to 23 μg/mL, representing about 0.1% of the GOS daily intake. In urine, approximately 0.85 g of GOS/g of creatinine was found. Cecum digesta and feces contained low amounts of oligosaccharides, suggesting an extensive GOS intestinal fermentation in piglets.

    Interacties tussen ijzerchelaten en andere spoorelementen vaak onderschat : analysecijfers tonen niet altijd wat beschikbaar is voor plant
    Staalduinen, J. van; Voogt, W. - \ 2015
    Onder Glas 12 (2015)5. - p. 10 - 11.
    glastuinbouw - voedingsstoffen - bemesting - ijzerhoudende meststoffen - plantenvoeding - ijzerabsorptie - chelaten - meststoffen met sporenelementen - absorptie - zuurgraad - substraten - recirculatiesystemen - irrigatiewater - greenhouse horticulture - nutrients - fertilizer application - iron fertilizers - plant nutrition - iron absorption - chelates - trace element fertilizers - absorption - acidity - substrates - recirculating systems - irrigation water
    IJzer is onder normale wortelcondities vaak moeilijk opneembaar voor planten. Dat geldt ook en misschien wel juist voor substraatteelten. IJzerchelaten – organische moleculen die ijzerionen adsorberen en afstaan aan of in plantenwortels – bieden uitkomst. Bij de keuze van het juiste chelaat dient men niet alleen oog te hebben voor de pH van de voedingsoplossing of in de mat. Zij kunnen ook verbindingen aangaan met andere spoorelementen, waardoor drainwateranalyse soms een vertekend beeld geeft van wat er werkelijk beschikbaar is.
    Bioavailability and biodistribution of differently charged polystyrene nanoparticles upon oral exposure in rats
    Walczak, A.P. ; Hendriksen, P.J.M. ; Woutersen, R.A. ; Zande, M. van der; Undas, A.K. ; Helsdingen, J.R. ; Berg, J.H.J. van den; Rietjens, I.M.C.M. ; Bouwmeester, H. - \ 2015
    Journal of Nanoparticle Research : an Interdisciplinary Forum for Nanoscale Science and Technology 17 (2015). - ISSN 1388-0764 - 13 p.
    zinc-oxide nanoparticles - titanium-dioxide nanoparticles - tissue distribution - silver nanoparticles - particle-size - absorption - food - translocation - microspheres - elimination
    The likelihood of oral exposure to nanoparticles (NPs) is increasing, and it is necessary to evaluate the oral bioavailability of NPs. In vitro approaches could help reducing animal studies, but validation against in vivo studies is essential. Previously, we assessed the translocation of 50 nm polystyrene NPs of different charges (neutral, positive and negative) using a Caco-2/HT29-MTX in vitro intestinal translocation model. The NPs translocated in a surface charge-dependent manner. The present study aimed to validate this in vitro intestinal model by an in vivo study. For this, rats were orally exposed to a single dose of these polystyrene NPs and the uptake in organs was determined. A negatively charged NP was taken up more than other NPs, with the highest amounts in kidney (37.4 µg/g tissue), heart (52.8 µg/g tissue), stomach wall (98.3 µg/g tissue) and small intestinal wall (94.4 µg/g tissue). This partly confirms our in vitro findings, where the same NPs translocated to the highest extent. The estimated bioavailability of different types of NPs ranged from 0.2 to 1.7 % in vivo, which was much lower than in vitro (1.6–12.3 %). Therefore, the integrated in vitro model cannot be used for a direct prediction of the bioavailability of orally administered NPs. However, the model can be used for prioritizing NPs before further in vivo testing for risk assessment.
    In vitro selenium accessibility in pet foods is affected by diet composition and type
    Zelst, M. van; Hesta, M. ; Alexander, L.G. ; Gray, K. ; Bosch, G. ; Hendriks, W.H. ; Laing, G. Du; Meulenaer, B. de; Goethals, K. ; Janssens, G. - \ 2015
    The British journal of nutrition 113 (2015)12. - ISSN 0007-1145 - p. 1888 - 1894.
    nutrient digestion - organic selenium - bioavailability - absorption - dog - bioaccessibility - selenomethionine - metabolism - prediction - fiber
    Se bioavailability in commercial pet foods has been shown to be highly variable. The aim of the present study was to identify dietary factors associated with in vitro accessibility of Se (Se Aiv) in pet foods. Se Aiv is defined as the percentage of Se from the diet that is potentially available for absorption after in vitro digestion. Sixty-two diets (dog, n 52; cat, n 10) were in vitro enzymatically digested: fifty-four of them were commercially available (kibble, n 20; pellet, n 8; canned, n 17; raw meat, n 6; steamed meat, n 3) and eight were unprocessed (kibble, n 4; canned, n 4) from the same batch as the corresponding processed diets. The present investigation examined if Se Aiv was affected by diet type, dietary protein, methionine, cysteine, lysine and Se content, DM, organic matter and crude protein (CP) digestibility. Se Aiv differed significantly among diet types (P<0·001). Canned and steamed meat diets had a lower Se Aiv than pelleted and raw meat diets. Se Aiv correlated positively with CP digestibility in extruded diets (kibbles, n 19; r 0·540, P =0·017) and negatively in canned diets (n 16; r - 0·611, P =0·012). Moreover, the canning process (n 4) decreased Se Aiv (P =0·001), whereas extrusion (n 4) revealed no effect on Se Aiv (P =0·297). These differences in Se Aiv between diet types warrant quantification of diet type effects on in vivo Se bioavailability.
    Fat coating of Ca butyrate results in extended butyrate release in the gastrointestinal tract of broilers
    Borne, J.J.G.C. van den; Heetkamp, M.J.W. ; Buyse, J. ; Niewold, T.A. - \ 2015
    Livestock Science 175 (2015). - ISSN 1871-1413 - p. 96 - 100.
    acid breath test - c-13-octanoic acid - chickens - absorption - passage
    Based on its described beneficial effects on small and large intestinal epithelium, butyrate can be a very good alternative to antimicrobial growth promoters. Effective dietary application requires coating because the majority of uncoated butyrate is purportedly absorbed before reaching the proximal small intestine. Several studies using different protocols reported varying stomach passage times in chickens. In the present study, we compared feeding uncoated vs. fat coated [1-13C] labeled Ca butyrate, and compared the effect of butyrate coating with [1-13C] labeled octanoic acid which is an established indicator of stomach passage. By monitoring 13CO2 expiration continuously, we show that the majority (about 80%) of uncoated Ca butyrate is oxidized proximally of the small intestine, and that base line levels were reached after 6 h. Fat coating of Ca butyrate resulted in reduced proximal oxidation (from about 80% to about 45%), and in an extended release pattern of 13CO2 from butyrate similar to that of octanoic acid, and that the return to base line levels was extended to 12 h. This indicated that fat coating of butyrate results in absorption along the entire intestinal tract in broilers, offering an explanation for the described beneficial effects as a growth promoter.
    Factors contributing to the variation in feline urinary oxalate excretion
    Dijcker, J.C. ; Hagen-Plantinga, E.A. ; Everts, H. ; Queau, Y. ; Biourge, V.C. ; Hendriks, W.H. - \ 2014
    Journal of Animal Science 92 (2014)3. - ISSN 0021-8812 - p. 1029 - 1036.
    glycolate excretion - dietary-protein - ascorbic-acid - calcium - cats - hydroxyproline - vitamin-b-6 - fructose - requirement - absorption
    This study aimed to identify factors (season, animal, and diet) contributing to the variation in urinary oxalate (Uox) excretion rate, Uox concentration, and urine volume in healthy adult cats. A data set (1,940 observations) containing information on Uox excretion rate of 65 cats fed 252 diets (i.e., each diet was fed to a group of 6 to 8 cats), with known dietary oxalate concentrations, collected over a 6 yr period at a feline nutrition facility, were retrospectively analyzed. Data related to season, animal (i.e., age, gender, body weight, and breed), and diet (i.e., nutrient content) characteristics were subjected to stepwise multivariate regression analysis to identify factors significantly correlated to Uox excretion rate (µmol/(kg BW0.67·d)) and concentration (mmol/L) as well as urine volume (mL/(kg BW0.67·d)). Independent factors significantly (P <0.05) associated with lower Uox concentration (mmol/L) included greater ash, Ca, and Na intake and lower nitrogen-free extract, total dietary fiber, P, and oxalate intake, and a body weight
    A higher proportion of Iron-Rich leafy vegatables in a typical burkinabe maize meal does not increase the amount of iron absorbed in young women
    Cercamondi, C.I. ; Icard-Verniere, C. ; Egli, I. ; Vernay, M. ; Hama, F. ; Brouwer, I.D. - \ 2014
    The Journal of Nutrition 144 (2014)9. - ISSN 0022-3166 - p. 1394 - 1400.
    phenolic-compounds - stable-isotope - pearl-millet - fortification iron - ascorbic-acid - phytic acid - in-field - absorption - foods - sorghum
    Food-to-food fortification can be a promising approach to improve the low dietary iron intake and bioavailability from monotonous diets based on a small number of staple plant foods. In Burkina Faso, the common diet consists of a thick, cereal-based paste consumed with sauces composed of mainly green leaves, such as amaranth and jute leaves. Increasing the quantity of leaves in the sauces substantially increases their iron concentration. To evaluate whether increasing the quantity of leaves in sauces would provide additional bioavailable iron, an iron absorption study in 18 young women was conducted in Zurich, Switzerland. Burkinabe composite test meals consisting of the maize paste tô accompanied by an iron-improved amaranth sauce, an iron-improved jute sauce, or a traditional amaranth sauce were provided as multiple meals twice a day for 2 consecutive days. Iron absorption was measured as erythrocyte incorporation of stable iron isotopes. Mean fractional iron absorption from maize paste consumed with an iron-improved amaranth sauce (4.9%) did not differ from the same meal consumed with an iron-improved jute sauce (4.9%; P = 0.9), resulting in a similar quantity of total iron absorbed (679 vs. 578 µg; P = 0.3). Mean fractional iron absorption from maize paste accompanied by a traditional amaranth sauce (7.4%) was significantly higher than that from the other 2 meal types (P <0.05), but the quantity of total iron absorbed was similar (591 µg; P = 0.4 and 0.7, respectively). A food-to-food fortification approach based on an increase in leafy vegetables does not provide additional bioavailable iron, presumably due to the high phenolic compound concentration of the leaves tested. Alternative measures, such as adding iron absorption enhancers to the sauces, need to be investigated to improve iron nutrition from Burkinabe maize meals.
    Food matrix effects on bioaccessibility of B-Carotene can be measured in a vitro gastrointestinal model
    Loo-Bouwman, C.A. van; Naber, T.H.J. ; Minekus, M. ; Hulshof, P.J.M. ; Schaafsma, G. - \ 2014
    Journal of Agricultural and Food Chemistry 62 (2014)4. - ISSN 0021-8561 - p. 950 - 955.
    green leafy vegetables - digestion method - pro-vitamin - folic-acid - accessibility - serum - bioavailability - absorption - retinol - cassava
    Since the food matrix determines ß-carotene availability for intestinal absorption, food matrix effects on the bioaccessibility of ß-carotene from two diets were investigated in vitro and compared with in vivo data. The “mixed diet” consisted of ß-carotene-rich vegetables, and the “oil diet” contained ß-carotene-low vegetables with supplemental ß-carotene. The application of extrinsically labeled ß-carotene was also investigated. The bioaccessibility of ß-carotene was 28 µg/100 µg ß-carotene from the mixed diet and 53 µg/100 µg ß-carotene from the oil diet. This ratio of 1.9:1 was consistent with in vivo data, where the apparent absorption was 1.9-fold higher in the oil diet than in the mixed diet. The labeled ß-carotene was not equally distributed over time. In conclusion, the food matrix effects on bioaccessibility of ß-carotene could be measured using an in vitro model and were consistent with in vivo data. The application of extrinsically labeled ß-carotene was not confirmed.
    A physiologically based kinetic (PBK) model describing plasma concentrations of quercetin and its metabolites in rats
    Boonpawa, R. ; Spenkelink, A. ; Rietjens, I. ; Punt, A. - \ 2014
    Biochemical Pharmacology 89 (2014)2. - ISSN 0006-2952 - p. 287 - 299.
    flavonoid-mediated inhibition - blood partition-coefficients - oral bioavailability - biological-activity - biliary-excretion - intestinal uptake - glucuronidation - humans - absorption - tissues
    Biological activities of flavonoids in vivo are ultimately dependent on the systemic bioavailability of the aglycones as well as their metabolites. In the present study, a physiologically based kinetic (PBK) model was developed to predict plasma concentrations of the flavonoid quercetin and its metabolites and to tentatively identify the regiospecificity of the major circulating metabolites. The model was developed based on in vitro metabolic parameters and by fitting kinetic parameters to literature available in vivo data. Both exposure to quercetin aglycone and to quercetin-4'-O-glucoside, for which in vivo data were available, were simulated. The predicted plasma concentrations of different metabolites adequately matched literature reported plasma concentrations of these metabolites in rats exposed to 4'-O-glucoside. The bioavailability of aglycone was predicted to be very low ranging from 0.004%-0.1% at different oral doses of quercetin or quercetin-4'-O-glucoside. Glucuronidation was a crucial pathway that limited the bioavailability of the aglycone, with 95–99% of the dose being converted to monoglucuronides within 1.5–2.5 h at different dose levels ranging from 0.1 to 50 mg/kg bw quercetin or quercetin-4'-O-glucoside. The fast metabolic conversion to monoglucuronides allowed these metabolites to further conjugate to di- and tri-conjugates. The regiospecificity of major circulating metabolites was observed to be dose-dependent. As we still lack in vivo kinetic data for many flavonoids, the developed model has a great potential to be used as a platform to build PBK models for other flavonoids as well as to predict the kinetics of flavonoids in humans.
    Predicting individual responses to pravastatin using a physiologically based kinetic model for plasma cholesterol levels
    Pas, N.C.A. van de; Rullmann, J. ; Woutersen, R.A. ; Ommen, B. van; Rietjens, I. ; Graaf, A.A. de - \ 2014
    Journal of Pharmacokinetics and Pharmacodynamics 41 (2014)4. - ISSN 1567-567X - p. 351 - 362.
    coa reductase inhibitors - statin therapy - lowering-therapy - ldl cholesterol - hepg2 cells - atorvastatin - simvastatin - absorption - metabolism - trial
    We used a previously developed physiologically based kinetic (PBK) model to analyze the effect of individual variations in metabolism and transport of cholesterol on pravastatin response. The PBK model is based on kinetic expressions for 21 reactions that interconnect eight different body cholesterol pools including plasma HDL and non-HDL cholesterol. A pravastatin pharmacokinetic model was constructed and the simulated hepatic pravastatin concentration was used to modulate the reaction rate constant of hepatic free cholesterol synthesis in the PBK model. The integrated model was then used to predict plasma cholesterol concentrations as a function of pravastatin dose. Predicted versus observed values at 40 mg/d pravastatin were 15 versus 22 % reduction of total plasma cholesterol, and 10 versus 5.6 % increase of HDL cholesterol. A population of 7,609 virtual subjects was generated using a Monte Carlo approach, and the response to a 40 mg/d pravastatin dose was simulated for each subject. Linear regression analysis of the pravastatin response in this virtual population showed that hepatic and peripheral cholesterol synthesis had the largest regression coefficients for the non-HDL-C response. However, the modeling also showed that these processes alone did not suffice to predict non-HDL-C response to pravastatin, contradicting the hypothesis that people with high cholesterol synthesis rates are good statin responders. In conclusion, we have developed a PBK model that is able to accurately describe the effect of pravastatin treatment on plasma cholesterol concentrations and can be used to provide insight in the mechanisms behind individual variation in statin response.
    The effect of fibers on coagulation of casein-based enteral nutrition in an artificial gastric digestion model
    Luttikhold, J. ; Norren, K. van; Minor, M. ; Buijs, N. ; Braak, C.C.M. van den; Ludwig, T. ; Abrahamse, E. ; Rijna, H. ; Leeuwen, P.A.M. - \ 2014
    Food & Function 5 (2014). - ISSN 2042-6496 - p. 1866 - 1871.
    critically-ill patients - thermodynamic incompatibility - intestinal-obstruction - in-vitro - motility - proteins - absorption - guidelines - mixtures - feedings
    A serious complication seen in critically ill patients is the solidification of enteral nutrition causing gastrointestinal obstruction. It has been suggested that enteral nutrition enriched with insoluble fibers may increase the risk of this complication. Therefore, we investigate the effect of soluble and insoluble dietary fibers on the coagulation of a casein-based enteral nutrition in an artificial gastric digestion model. A 100% casein-based enteral nutrition was enriched with increasing concentrations of soluble fibers (acacia fiber, oligofructose and inulin) and insoluble fibers (soy polysaccharide, resistant starch and alpha cellulose). After digestion in an artificial gastric model, the chyme was poured over sequentially placed sieves, separating the coagulate into size fractions of larger than 2 mm, between 1 and 2 mm, and between 0.25 and 1 mm. Of these fractions we measured wet weight, dry weight and protein content. A significant effect on the fraction larger than 2 mm was considered to be clinically relevant. Addition of high concentrations soy polysaccharide and resistant starch to a casein-based enteral nutrition, did not alter the wet weight, whereas dry weight and protein content of the coagulate was significantly reduced. When high concentrations of soy polysaccharide and resistant starch are added to a 100% casein-based enteral nutrition, the coagulate consist of more water and less proteins, which may lead to an increased protein digestion and absorption in a clinical setting. The suggestion that insoluble fibers increase the risk of gastrointestinal obstruction in critically ill patients is not supported by these data.
    The effect of steam pelleting of a dry dog food on the Maillard reaction
    Rooijen, C. van; Bosch, G. ; Wierenga, P.A. ; Hendriks, W.H. ; Poel, A.F.B. van der - \ 2014
    Animal Feed Science and Technology 198 (2014). - ISSN 0377-8401 - p. 238 - 247.
    glycation end-products - physical quality - nutritive-value - animal feed - lysine - diet - digestibility - absorption - components - proteins
    During processing of pet foods, the Maillard reaction (MR) can occur, which reduces the bioavailability of essential amino acids like lysine and results in the formation of advanced Maillard reaction products (MRPs). This study examined the effect of conditioning temperature (65 and 90 °C) and die hole length (ø 5 × 45, 65, and 80 mm) during pelleting processing of a standard dry dog food on selected indicators of the MR (total lysine, reactive lysine, fructoselysine, ¿-N-carboxymethyllysine, (5-hydroxymethyl)-2-furfural, lysinoalanine), browning development and CIE-Lab color. Steam pelleting variables did not cause a significant loss of lysine or change in color and absorbance values. Analyzing the unprocessed ingredient mix suggests that the choice of the ingredients used in the ingredient mix, rather than the pelleting process applied, is responsible for the RL/TL ratio observed in the dry standard dog food used in this study. MRP content increased during steam pelleting (fructoselysine: 366.2 to 538.8 mg/kg DM; ¿-N-carboxymethyllysine: 12.6 to 14.8 mg/kg DM; lysinoalanine: 5.7 to 7.7 mg/kg DM; P <0.05). Increasing conditioning temperature from 65 to 90 °C increased fructoselysine (475.9 to 601.6 mg/kg DM; P <0.01) and ¿-N-carboxymethyllysine (14.3 to 15.1 mg/kg DM; P = 0.003). An increased die hole length of 80 mm decreased fructoselysine content compared to 45 and 65 mm (461.3 vs. 573.3 and 581.6 mg/kg DM; P <0.01) but increased lysinoalanine content (8.8 vs. 7.4 and 6.8 mg/kg DM; P = 0.002). Analyzing total and reactive lysine and absorbance values are not accurate enough to predict the MR and formation of MRPs during processing.
    Electroactive behavior assessment of poly(acrylic acid)-graphene oxide composite hydrogel in the detection of cadmium
    Bejarano-Jimenez, A. ; Escobar-Barrios, V.A. ; Kleijn, J.M. ; Oritz-Ledon, C.A. ; Chazaro-Ruiz, L.F. - \ 2014
    Journal of Applied Polymer Science 131 (2014)19. - ISSN 0021-8995 - 10 p.
    carbon-paste electrodes - swelling properties - metal-ions - acid) - polymerization - gels - complexation - absorption - water - ph
    Super absorbent polymers of acrylic acid-graphene oxide (PAA-GO) were synthesized with different percentage of chemical neutralization (0, 10, and 20%) of the acrylic acid monomer before its polymerization. The influence of their swelling and adsorption/desorption capacity of cadmium ions in aqueous solutions were studied and revealed that the GO enables greater mechanical stability in the materials. The PAA hydrogels, with the same degrees of neutralization, were also prepared without GO to compare with the composites. Additionally, carbon paste electrodes (CPE) modified with the composites PAA-GO were used to asses and compare their adsorption properties with cadmium(II). The anodic stripping voltammetry (ASV) peak, in the differential pulse voltammetry mode, for cadmium oxidation was found to be influenced by the presence of GO into the polymer, and also by their percentage of neutralization. The accumulation of cadmium(II) on the surface of the modified CPEs was performed under open-circuit conditions taking an account the preconcentration time of the metal cation. The presence of GO enhances the electrical signal of the electrodes in short times of immersion in cadmium(II) solutions. This property contributed to get linear responses of the CPEs modified with the composites, which were influenced by their degrees of neutralization. The PAA-GO 10N electrode with 10% of neutralization combined the influence of GO and the degree of neutralization in the same matrix, and also showed good performance in terms of its mechanical stability, it was chosen for preliminary studies on the selectivity of the electrode toward Zn(II) and Cu(II).
    Peripartal calcium homoeostasis of multiparous dairy cows fed rumen-protected rice bran or a lowered dietary cation/anion balance diet before calving
    Martin-Tereso, J. ; Wijlen, H. ter; Laar, H. van; Verstegen, M.W.A. - \ 2014
    Journal of Animal Physiology and Animal Nutrition 98 (2014)4. - ISSN 0931-2439 - p. 775 - 784.
    anion difference - milk fever - dry period - hypocalcemia - metaanalysis - absorption - disorders - nutrition - health - cattle
    Milk fever is one of the most important metabolic diseases in dairy cattle. Reducing the dietary cation/anion balance (DCAD) with anionic salts is a common prevention strategy. However, many small European farms cannot use total mixed rations (TMR) in the close-up period. Including anionic salts in compound feeds can result in feed refusals and moderate inclusions to preserve feed palatability results in insufficient DCAD reduction. Rumen-protected rice bran induces the adaptation of Ca metabolism in dairy cows by a reduction of Ca intake and by a reduction of the availability of dietary Ca. In the presence of a negative control, rumen-protected rice bran (2.8 kg/day) was compared with a lowered DCAD diet (from 269 to 4 meq/kg DM) in their effect to prevent milk fever. In a randomized block design, 45 multiparous Holstein cows joined the trial sequentially from 21 days before the expected calving date and were observed until the 8th week of lactation. Feed and nutrient intakes were recorded, and Ca, P, Mg in serum and urine, urine pH, serum NEFA and milk production in early lactation were compared. Feeding rumen-protected rice bran before calving improved the recovery of calcaemia after calving and had a positive effect on DMI after calving. The moderately low DCAD diet did not positively influence serum Ca at calving. Calcaemia recovered even later than in control, and cows showed reduced DMI post-calving and higher NEFA levels in the first 36 h after calving. This moderate reduction of DCAD did not provide an intermediate prevention level indicating that DCAD needs to be reduced to the recommended levels to prevent milk fever. Rumen-protected rice bran may be a suitable feed to reduce hypocalcaemia post-partum and can be included in pre-calving compound feeds representing a palatable alternative to anionic salts.
    Efficacy of dimethylglycine as a feed additive to improve broiler production
    Kalmar, I.D. ; Verstegen, M.W.A. ; Vanrompay, D. ; Maenner, K. ; Zentek, J. ; Iben, C. ; Leitgeb, R. ; Schiavone, A. ; Prola, L. ; Janssens, G. - \ 2014
    Livestock Science 164 (2014). - ISSN 1871-1413 - p. 81 - 86.
    amino-acids - n,n-dimethylglycine - supplementation - digestibility - performance - absorption - choline - betaine - diet
    Dimethylglycine (DMG) is a naturally occurring glycine derivative, which is useful as additive to broiler diets as it improves nutrient digestibility and reduces the development of broiler ascites syndrome. This study evaluated the efficacy of dietary DMG to enhance performance of broiler chickens. Three trials were conducted to evaluate the effect of dietary supplementation with 1 g Na DMG/kg on growth performance and carcass characteristics. In Trial 1, the effect of sex was also assessed in a 2×2 factorial arrangement of treatments. In Trials 1 (Germany), 2 (Austria), and 3 (Italy), each treatment consisted of 6, 12, and 11 replicate pens with 20, 15, and 16 one-day-old broiler chickens per pen, respectively. Dietary DMG supplementation resulted in improved feed conversion ratio (FCR) in the starter phase by 8.8% (P=0.004), 6.4% (P=0.001), and 4.8% (P=0.006) compared with the control diet in Trials 1, 2, and 3, respectively. The overall FCR improved in broiler chickens fed the diets supplemented with DMG by 3.8% and 4.1% in Trials 1 (P=0.007) and 3 (P=0.006), respectively. In addition, final body weight increased by 5.5% (P=0.001) in Trial 2 and production value improved by 6.8% (P=0.015) in Trial 1 by dietary DMG supplementation. Mortality in all trials was similar between dietary treatments. In all 3 trials, cold carcass weight and total meat yield were as well similar between broiler chickens fed the control and DMG diets. In Trial 1, dietary DMG had no effect on breast meat yield in male broiler chickens, but it increased breast meat yield in female broiler chickens (diet×sex, P=0.004). Organoleptic quality of roasted breast meat assessed only in Trial 2 was not affected by dietary treatments. In conclusion, dietary supplementation of DMG at 1 g Na DMG/kg can considerably improve s production performance in broiler chickens.
    Conversion of major soy isoflavone glucosides and aglycones in in vitro intestinal models
    Islam, M.A. ; Punt, A. ; Spenkelink, A. ; Murk, A.J. ; Leeuwen, F.X.R. ; Rietjens, I. - \ 2014
    Molecular Nutrition & Food Research 58 (2014)3. - ISSN 1613-4125 - p. 503 - 515.
    rat small-intestine - lactase-phlorhizin hydrolase - caco-2 cell monolayers - beta-glucosidase - 1st-pass metabolism - phyto-estrogens - human plasma - absorption - bioavailability - glycosides
    ScopeThis study compares conversion of three major soy isoflavone glucosides and their aglycones in a series of in vitro intestinal models. Methods and resultsIn an in vitro human digestion model isoflavone glucosides were not deconjugated, whereas studies in a Caco-2 transwell model confirmed that deconjugation is essential to facilitate transport across the intestinal barrier. Deconjugation was shown upon incubation of the isoflavone glucosides with rat as well as human intestinal S9. In incubations with rat intestinal S9 lactase phlorizin hydrolase, glucocerebrosidase, and cytosolic broad-specific -glucosidase all contribute significantly to deconjugation, whereas in incubations with human intestinal S9 deconjugation appeared to occur mainly through the activity of broad-specific -glucosidase. Species differences in glucuronidation and sulfation were limited and generally within an order of magnitude with 7-O-glucuronides being the major metabolites for all three isoflavone aglycones and the glucuronidation during first pass metabolism being more efficient in rats than in humans. Comparison of the catalytic efficiencies reveals that deconjugation is less efficient than conjugation confirming that aglycones are unlikely to enter the systemic circulation. ConclusionAltogether, the data point at possible differences in the characteristics for intestinal conversion of the major soy isoflavones between rat and human, especially with respect to their deconjugation.
    Quantum Chemical Studies on Solvents for Post-Combustion Carbon Dioxide Capture: Calculation of pKa and Carbamate Stability of Disubtituted Piperazines
    Gangarapu, S. ; Wierda, G.J. ; Marcelis, A.T.M. ; Zuilhof, H. - \ 2014
    ChemPhysChem 15 (2014). - ISSN 1439-4235 - p. 1880 - 1886.
    sterically hindered amines - co2 capture - aqueous piperazine - pilot-plant - absorption - performance - technology - basicities - parameters - constants
    Piperazine is a widely studied solvent for post-combustion carbon dioxide capture. To investigate the possibilities of further improving this process, the electronic and steric effects of CH3, CH2F, CH2OH, CH2NH2, COCH3, and CN groups of 2,5-disubstituted piperazines on the pKa and carbamate stability towards hydrolysis are investigated by quantum chemical methods. For the calculations, B3LYP, M11L, and spin-component-scaled MP2 (SCS-MP2) methods are used and coupled with the SMD solvation model. The experimental pKa values of piperazine, 2-methylpiperazine, and 2,5-dimethylpiperazine agree well with the calculated values. The present study indicates that substitution of CH3, CH2NH2, and CH2OH groups on the 2- and 5-positions of piperazine has a positive impact on the CO2 absorption capacity by reducing the carbamate stability towards hydrolysis. Furthermore, their higher boiling points, relative to piperazine itself, will lead to a reduction of volatility-related losses.
    Theory of ion transport with fast acid-base equilibrations in bioelectrochemical systems
    Dykstra, J.E. ; Biesheuvel, P.M. ; Bruning, H. ; Heijne, A. ter - \ 2014
    Physical Review. E, Statistical nonlinear, and soft matter physics 90 (2014). - ISSN 1539-3755 - 10 p.
    microbial electrolysis cell - hydrogen-production - fuel-cells - quantitative approach - mathematical-model - ammonium recovery - chemical-reaction - inorganic carbon - urine - absorption
    Bioelectrochemical systems recover valuable components and energy in the form of hydrogen or electricity from aqueous organic streams. We derive a one-dimensional steady-state model for ion transport in a bioelectrochemical system, with the ions subject to diffusional and electrical forces. Since most of the ionic species can undergo acid-base reactions, ion transport is combined in our model with infinitely fast ion acid-base equilibrations. The model describes the current-induced ammonia evaporation and recovery at the cathode side of a bioelectrochemical system that runs on an organic stream containing ammonium ions. We identify that the rate of ammonia evaporation depends not only on the current but also on the flow rate of gas in the cathode chamber, the diffusion of ammonia from the cathode back into the anode chamber, through the ion exchange membrane placed in between, and the membrane charge density.
    In Silico Prediction and Automatic LC–MSn Annotation of Green Tea Metabolites in Urine
    Ridder, L.O. ; Hooft, J.J.J. van der; Verhoeven, S. ; Vos, R.C.H. de; Vervoort, J.J.M. ; Bino, R.J. - \ 2014
    Analytical Chemistry 86 (2014)10. - ISSN 0003-2700 - p. 4767 - 4774.
    human fecal microbiota - mass-spectrometry - structural elucidation - human plasma - phenolic-compounds - spectral trees - polyphenols - identification - absorption - metabolomics
    The colonic breakdown and human biotransformation of small molecules present in food can give rise to a large variety of potentially bioactive metabolites in the human body. However, the absence of reference data for many of these components limits their identification in complex biological samples, such as plasma and urine. We present an in silico workflow for automatic chemical annotation of metabolite profiling data from liquid chromatography coupled with multistage accurate mass spectrometry (LC-MSn), which we used to systematically screen for the presence of tea-derived metabolites in human urine samples after green tea consumption. Reaction rules for intestinal degradation and human biotransformation were systematically applied to chemical structures of 75 green tea components, resulting in a virtual library of 27¿245 potential metabolites. All matching precursor ions in the urine LC–MSn data sets, as well as the corresponding fragment ions, were automatically annotated by in silico generated (sub)structures. The results were evaluated based on 74 previously identified urinary metabolites and lead to the putative identification of 26 additional green tea-derived metabolites. A total of 77% of all annotated metabolites were not present in the Pubchem database, demonstrating the benefit of in silico metabolite prediction for the automatic annotation of yet unknown metabolites in LC–MSn data from nutritional metabolite profiling experiments.
    Sub-chronic toxicity study in rats orally exposed to nanostructured silica
    Zande, M. van der; Vandebriel, R.J. ; Groot, M.J. ; Kramer, E.H.M. ; Herrera Riviera, Z.E. ; Rasmussen, K. ; Ossenkoppele, J.S. ; Tromp, P. ; Gremmer, E.R. ; Peters, R.J.B. ; Hendriksen, P.J. ; Marvin, H.J.P. ; Hoogenboom, L.A.P. ; Peijnenburg, A.A.C.M. ; Bouwmeester, H. - \ 2014
    Particle and Fibre Toxicology 11 (2014). - ISSN 1743-8977
    in-vivo biodistribution - expression profiles - liver fibrosis - nanoparticles - absorption - elimination - injection - foods - acid - size
    Synthetic Amorphous Silica (SAS) is commonly used in food and drugs. Recently, a consumer intake of silica from food was estimated at 9.4 mg/kg bw/day, of which 1.8 mg/kg bw/day was estimated to be in the nano-size range. Food products containing SAS have been shown to contain silica in the nanometer size range (i.e. 5 – 200 nm) up to 43% of the total silica content. Concerns have been raised about the possible adverse effects of chronic exposure to nanostructured silica.
    Compensation in Root Water Uptake Models Combined with Three-Dimensional Root Length Density Distribution
    Heinen, M. - \ 2014
    Vadose Zone Journal 13 (2014)2. - ISSN 1539-1663 - 9 p.
    hydraulic architecture - integrated approach - porous-media - absorption - conductivity - systems - soils
    A three-dimensional root length density distribution function is introduced that made it possible to compare two empirical uptake models with a more mechanistic uptake model. Adding a compensation component to the more empirical model resulted in predictions of root water uptake distributions similar to those predicted by the more complex model. Because root water uptake is a considerable component in the soil water balance, a lot of attention has been paid to defining and applying root water uptake models. These models can be grouped into empirical vs. mechanistic root uptake models. Intermodel comparisons are valuable in understanding the different concepts used. Such a comparison is sometimes difficult because the level of information required by the models is different, for example, information on the root length density distribution. Here a three-dimensional root length density distribution function is introduced that makes it possible to compare two empirical uptake models with a more mechanistic uptake model. Adding a compensation component to the more empirical model results in prediction of root water uptake distributions in the root zone similar to those predicted by the more complex model.
    Minimizing measurement uncertainties of coniferous needle-leaf optical properties, part I: methodological review
    Yanez Rausell, L. ; Schaepman, M.E. ; Clevers, J.G.P.W. ; Malenovsky, Z. - \ 2014
    IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing 7 (2014)2. - ISSN 1939-1404 - p. 399 - 405.
    revised measurement methodology - chlorophyll content estimation - radiative-transfer model - reflectance spectra - hyperspectral data - bifacial leaf - boreal forest - leaves - light - absorption
    Optical properties (OPs) of non-flat narrow plant leaves, i.e., coniferous needles, are extensively used by the remote sensing community, in particular for calibration and validation of radiative transfer models at leaf and canopy level. Optical measurements of such small living elements are, however, a technical challenge and only few studies attempted so far to investigate and quantify related measurement errors. In this paper we review current methods and developments measuring optical properties of narrow leaves. We discuss measurement shortcomings and knowledge gaps related to a particular case of non-flat nonbifacial coniferous needle leaves, e.g., needles of Norway spruce (Picea abies (L.) Karst.).
    Optimizing illumination in the greenhouse using a 3D model of tomato and a ray tracer
    Visser, P.H.B. de; Buck-Sorlin, G.H. ; Heijden, G.W.A.M. van der - \ 2014
    Frontiers in Plant Science 5 (2014). - ISSN 1664-462X - 7 p.
    structural plant-model - light interception - cucumber canopies - photosynthesis - simulation - environment - absorption
    Reduction of energy use for assimilation lighting is one of the most urgent goals of current greenhouse horticulture in the Netherlands. In recent years numerous lighting systems have been tested in greenhouses, yet their efficiency has been very difficult to measure in practice. This simulation study evaluated a number of lighting strategies using a 3D light model for natural and artificial light in combination with a 3D model of tomato. The modeling platform GroIMP was used for the simulation study. The crop was represented by 3D virtual plants of tomato with fixed architecture. Detailed data on greenhouse architecture and lamp emission patterns of different light sources were incorporated in the model. A number of illumination strategies were modeled with the calibrated model. Results were compared to the standard configuration. Moreover, adaptation of leaf angles was incorporated for testing their effect on light use efficiency (LUE). A Farquhar photosynthesis model was used to translate the absorbed light for each leaf into a produced amount of carbohydrates. The carbohydrates produced by the crop per unit emitted light from sun or high pressure sodium lamps was the highest for horizontal leaf angles or slightly downward pointing leaves, and was less for more upward leaf orientations. The simulated leaf angles did not affect light absorption from inter-lighting LED modules, but the scenario with LEDs shining slightly upward (20°) increased light absorption and LUE relative to default horizontal beaming LEDs. Furthermore, the model showed that leaf orientation more perpendicular to the string of LEDs increased LED light interception. The combination of a ray tracer and a 3D crop model could compute optimal lighting of leaves by quantification of light fluxes and illustration by rendered lighting patterns. Results indicate that illumination efficiency increases when the lamp light is directed at most to leaves that have a high photosynthetic potential. - See more at: http://journal.frontiersin.org/Journal/10.3389/fpls.2014.00048/abstract#sthash.oZ0vUtYM.dpuf
    Energy from CO2 using capacitive electrodes – Theoretical outline and calculation of open circuit voltage
    Par-Garcia, J.M. ; Schaetzle, O. ; Biesheuvel, P.M. ; Hamelers, H.V.M. - \ 2014
    Journal of Colloid and Interface Science 418 (2014). - ISSN 0021-9797 - p. 200 - 207.
    anion-exchange membranes - porous-electrodes - carbamate formation - aqueous-solution - acid anions - monoethanolamine - equilibrium - absorption - simulation - capture
    Recently, a new technology has been proposed for the utilization of energy from CO2 emissions (Hamelers et al., 2014). The principle consists of controlling the dilution process of CO2–concentrated gas (e.g., exhaust gas) into CO2–dilute gas (e.g., air) thereby extracting a fraction of the released mixing energy. In this paper, we describe the theoretical fundamentals of this technology when using a pair of charge–selective capacitive electrodes. We focus on the behavior of the chemical system consisting of CO2 gas dissolved in water or monoethanolamine solution. The maximum voltage given for the capacitive cell is theoretically calculated, based on the membrane potential. The different aspects that affect this theoretical maximum value are discussed.
    Assessing environmental consequences of using co-products in animal feed
    Zanten, H.H.E. van; Mollenhorst, H. ; Vries, J.W. de; Middelaar, C.E. van; Kernebeek, H.R.J. van; Boer, I.J.M. de - \ 2014
    The International Journal of Life Cycle Assessment 19 (2014)1. - ISSN 0948-3349 - p. 79 - 88.
    bio-energy - digestion - impact - rumen - perspective - absorption - manure - tract - model
    The livestock sector has a major impact on the environment. This environmental impact may be reduced by feeding agricultural co-products (e.g. beet tails) to livestock, as this transforms inedible products for humans into edible products, e.g. pork or beef. Nevertheless, co-products have different applications such as bioenergy production. Based on a framework we developed, we assessed environmental consequences of using co-products in diets of livestock, including the alternative application of that co-product. We performed a consequential life cycle assessment, regarding greenhouse gas emissions (including emissions related to land use change) and land use, for two case studies. Case 1 includes increasing the use of wheat middlings in diets of dairy cattle at the expense of using it in diets of pigs. The decreased use of wheat middlings in diets of pigs was substituted with barley, the marginal product. Case 2 includes increasing the use of beet tails in diets of dairy cattle at the expense of using it to produce bioenergy. During the production of biogas, electricity, heat and digestate (that is used as organic fertilizer) were produced. The decrease of electricity and heat was substituted with fossil fuel, and digestate was substituted with artificial fertilizer. Using wheat middlings in diets of dairy cattle instead of using it in diets of pigs resulted in a reduction of 329 kg CO2 eq per ton wheat middlings and a decrease of 169 m(2) land. Using beet tails in diets of dairy cattle instead of using it as a substrate for anaerobic digestion resulted in a decrease of 239 kg CO2 eq per ton beet tails and a decrease of 154 m(2) land. Emissions regarding land use change contributed significantly in both cases but had a high uncertainty factor, +/- 170 ton CO2 ha(-1). Excluding emissions from land use change resulted in a decrease of 9 kg CO2 eq for case 1 'wheat middlings' and an increase of 50 kg CO2 eq for case 2 'beet tails'. Assessing the use of co-products in the livestock sector is of importance because shifting its application can reduce the environmental impact of the livestock sector. A correct assessment of the environmental consequences of using co-products in animal feed should also include potential changes in impacts outside the livestock sector, such as the impact in the bioenergy sector.
    Novel multi-sugar assay for site-specific gastrointestinal permeability analysis: A randomized controlled crossover trial
    Wijck, K. van; Verlinden, T.J.M. ; Eijk, H.M.H. van; Dekker, J. ; Buurman, W.A. ; Dejong, C.H.C. ; Lenaerts, K. - \ 2013
    Clinical Nutrition 32 (2013)2. - ISSN 0261-5614 - p. 245 - 251.
    nonsteroidal antiinflammatory drugs - intestinal permeability - humans - mannitol - nsaid - indomethacin - absorption - lactulose - rat - enteropathy
    Background & aims: Increased gastrointestinal (GI) permeability is an important hallmark of many conditions, potentially leading to antigen exposure and sepsis. Current permeability tests are hampered by analytical limitations. This study aims to compare the accuracy of our multi-sugar (MS) and the classical dual sugar (DS) test for detection of increased GI permeability. Methods: Ten volunteers received permeability analysis using MS (1 g sucrose, lactulose, sucralose, erythritol, 0.5 g rhamnose in water) or DS (5 g lactulose, 0.5 g rhamnose), after indomethacin or placebo. Blood and urine were analyzed by isocratic LC-MS. Results: MS testing revealed significantly elevated urinary lactulose/rhamnose (L/R) ratios after indomethacin, due to enhanced lactulose excretion (P <.01) and unaltered rhamnose excretion. The DS test showed increased L/R ratios, due to increased lactulose excretion and decreased rhamnose excretion (both P <.05). After indomethacin, plasma L/R increased in both assays (P <.05 and P <.01). Urinary and plasma L/R ratios correlated significantly. Indomethacin increased sucrose excretion and 0-1 h sucrose/rhamnose. Colon permeability was unchanged. Conclusions: Sensitive permeability analysis is feasible in plasma and urine using MS or DS test. In contrast to the DS test, monosaccharide excretion is not decreased by the MS test. In short, the MS test provides accurate, site-specific information on gastroduodenal, small, and large intestinal permeability. Registered at US National Library of Medicine (http://www.clinicaltrials.gov, NCT00943345). (C) 2012 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
    Simulation of the effect of maize porridge fortified with grain amaranth or micronutrient powder containing NaFeEDTA on iron intake and status in Kenyan children
    Macharia-Mutie, C.W. ; Omusundi, A.M. ; Mwai, J.M. ; Mwangi, A.M. ; Brouwer, I.D. - \ 2013
    Public Health Nutrition 16 (2013)9. - ISSN 1368-9800 - p. 1605 - 1613.
    preschool-children - body iron - deficiency - absorption - anemia - women - trial - foods - biofortification - bioavailability
    Objective: Simulating the probable impact of grain amaranth and highly absorbable, low-Fe micronutrient powder (MNP) on Fe status in a potential target population is an essential step in choosing and developing an appropriate actual intervention. Design: We simulated the potential effect of fortifying maize porridge with grain amaranth or MNP on the prevalence of inadequate Fe intake and Fe deficiency using data from two cross-sectional surveys. In the first survey (2008), dietary intake data were collected by two 24 h recalls (n 197). Biochemical data (n 70) were collected in the second survey (2010). A simulation with daily consumption for 80 d of non-fortified maize porridge (60 g of maize flour), amaranth-enriched porridge (80 g of grain amaranth-maize flour, 70: 30 ratio) or maize porridge fortified with MNP (2.5 mg Fe as NaFeEDTA) was done. Setting: Mwingi District, Kenya. Subjects: Pre-school children aged 12-23 months. Results: Prevalence of anaemia, Fe deficiency and Fe-deficiency anaemia was 49%, 46% and 24%, respectively. Consumption of non-fortified, amaranth-enriched and MNP-fortified maize porridge was estimated to provide a median daily Fe intake of 8.6 mg, 17.5 mg and 11.1 mg, respectively. The prevalence of inadequate Fe intake was reduced to 35% in the amaranth-enriched porridge group and 45% in the MNP-fortified porridge group, while ferritin concentration was increased in both (by 1.82 (95% CI 1.42, 2.34) mu g/l and 1.80 (95% CI 1.40, 2.31) mu g/l, respectively; P
    Glucose and calcium ions may modulate the efficiency of bovine B-casomorphin-7 permeability through a monolayer of Caco-2 cells
    Jarmolowska, B. ; Teodorowicz, M. ; Fiedorowicz, E. ; Sienkiewicz-Szlapka, E. ; Matysiewicz, M. ; Kostyra, E. - \ 2013
    Peptides 49 (2013). - ISSN 0196-9781 - p. 59 - 67.
    beta-casomorphin - opioid-peptides - tight junctions - endothelial permeability - intestinal permeability - gene-expression - transport - milk - absorption - iv
    Milk and dairy products provide a lot of valuable nutritive elements. They are also sources of biologically active peptides, including ß-casomorphins that manifest the properties of morphine. An activity of DPPIV seems to be most crucial factor decreasing the efficiency of the ß-casomorphin-7 (BCM7) transport. The increase of BCM7 concentration in blood may intensify symptoms of apparent life threatening events (ALTE), autism, schizophrenia, and allergy. This study aimed at identifying the influence of several selected substances on a transport efficiency of bovine BCM7 through an intestinal monolayer in a Caco-2 cell model system. Applying the ELISA method, the permeability coefficient of BCM7 through the Caco-2 monolayer was calculated. TEER values were used to evaluate the integrity of Caco-2 cell monolayers. An increase of glucose and Ca(2+) concentrations in the culture medium was accompanied by an increase of the BCM7 transport efficiency. The lowest permeability coefficients of BCM7 were observed for the membranes with high electrical resistances. The transport was enhanced in the presence of milk infant formulas, whereas no changes were observed when using µ-opioid receptor antagonist (casoxin-6). The results may be useful in understanding the pathogenesis of inflammation and food allergy in infants.
    Carbamate Stabilities of Sterically Hindered Amines from Quantum Chemical Methods: Relevance ofr CO2 Capture
    Gangarapu, S. ; Marcelis, A.T.M. ; Zuilhof, H. - \ 2013
    ChemPhysChem 14 (2013)17. - ISSN 1439-4235 - p. 3936 - 3943.
    free-energy perturbations - carbon-dioxide - reaction-kinetics - aqueous-solutions - initio methods - absorption - 2-amino-2-methyl-1-propanol - methyldiethanolamine - monoethanolamine - technology
    The influence of electronic and steric effects on the stabilities of carbamates formed from the reaction of CO2 with a wide range of alkanolamines was investigated by quantum chemical methods. For the calculations, B3LYP, M11-L, MP2, and spin-component-scaled MP2 (SCS-MP2) methods were used, coupled with SMD and SM8 solvation models. A reduction in carbamate stability leads to an increased CO2 absorption capacity of the amine and a reduction of the energy required for solvent regeneration. Important factors for the reduction of the carbamate stability were an increase in steric hindrance around the nitrogen atom, charge on the N atom and intramolecular hydrogen bond strength. The present study indicates that secondary ethanolamines with sterically hindering groups near the N atom show significant potential as candidates for industrial CO2-capture solvents.
    Comparison of ileal and total tract nutrient digestibility of dry dog foods
    Hendriks, W.H. ; Thomas, G. ; Bosch, G. ; Fahey, G.C. - \ 2013
    Journal of Animal Science 91 (2013)8. - ISSN 0021-8812 - p. 3807 - 3814.
    amino-acid-composition - endogenous nitrogen - reactive lysine - protein - pigs - diets - bioavailability - ingredients - absorption - intestine
    The apparent total tract and ileal digestibility assays to measure AA absorption in commercial canine diets were compared in the present study. Five ileal cannulated dogs were fed 5 commercial dry canine foods selected to contain 19 to 30% CP in a 5 × 5 Latin square design. Ileal and total tract digestibility (apparent and standardized) of DM, OM, CP, crude fat (CF), carbohydrate, and AA (including reactive Lys) were calculated using Cr2O3 as an indigestible marker. Greater apparent total tract digestibility values were found for DM, OM, and CP (P = 0.034) compared with ileal digestibility values; however, CF (P = 0.058) had a greater ileal apparent digestibility. Apparent and standardized CP digestibility values were, respectively, 5.7 and 7.4 percentage units greater when measured over the total digestive tract compared with measurement at the ileum (P = 0.034 and 0.011, respectively). Ileal apparent digestibility for N of AA (P = 0.009) and most AA (P <0.05), except for Met, Ile, Lys, Phe, and Ala, was decreased if measured at the ileum. However, correction for endogenous losses showed only Met digestibility did not differ between measurement sites. Differences between sites in excess of 15 percentage units were recorded for AA. Apparent and standardized ileal reactive Lys digestibility was 3.1 to 15.3 percentage units greater than corresponding total tract digestibility values. For several indispensable AA, the bioavailability estimates currently used by the 2006 NRC and the 2011 Association of American Feed Control Officials to derive allowance estimates for canine adult maintenance were greater than the digestibility values of these AA in the commercial dog foods evaluated. Although the canine large intestine is relatively short, the total tract digestibility assay in dogs can overestimate the digestibility of dietary AA and CP and may not be an accurate method for the measurement of absorption. In this study, bioavailability estimates of AA appeared to be less than those used to derive allowance estimates for commercial dog foods. Further work is required if current recommendations warrant adjustment.
    Investigating the Transport Dynamics of Anthocyanins from Unprocessed Fruit and Processed Fruit Juice from Sour Cherry (Prunus cerasus L.) across Intestinal Epithelial Cells
    Toydemir, G. ; Boyacioglu, D. ; Capanoglu, E. ; Meer, I.M. van der; Tomassen, M.M.M. ; Hall, R.D. ; Mes, J.J. ; Beekwilder, J. - \ 2013
    Journal of Agricultural and Food Chemistry 61 (2013)47. - ISSN 0021-8561 - p. 11434 - 11441.
    red grape juice - protein interactions - cellular uptake - absorption - quercetin - dietary - caco-2 - bioavailability - consumption - glucosides
    Anthocyanins can contribute to human health through preventing a variety of diseases. The uptake of these compounds from food and the parameters determining uptake efficiency within the human body are still poorly understood. Here we have employed a Caco-2 cell based system to investigate the transport of key antioxidant food components from sour cherry (Prunus cerasus L.) across the intestinal epithelial barrier. Anthocyanins and (-)-epicatechin were supplied in three contrasting matrices: fruit, processed fruit cherry juice, and polyphenolic fractions obtained by solid-phase extraction. Results show that both compound types behave differently. Fruit or juice matrices display comparable transport across the epithelial cell layer. The juice supplements sucrose and citric acid, which are regularly added to processed foods, have a positive effect on stability and transport. Polyphenolic fractions display a lower transport efficiency, relative to that of the fruit or juice, indicating the importance of food matrix components for intestinal absorption of polyphenols
    Interpreting experimental data on egg production - applications of dynamic differential equations
    France, J. ; Lopez, S. ; Kebreab, E. ; Dijkstra, J. - \ 2013
    Poultry Science 92 (2013)9. - ISSN 0032-5791 - p. 2498 - 2508.
    drosophila-melanogaster - gastrointestinal-tract - quantitative genetics - mathematical-models - phosphorus - calcium - absorption - fertility - algorithm
    This contribution focuses on applying mathematical models based on systems of ordinary first-order differential equations to synthesize and interpret data from egg production experiments. Models based on linear systems of differential equations are contrasted with those based on nonlinear systems. Regression equations arising from analytical solutions to linear compartmental schemes are considered as candidate functions for describing egg production curves, together with aspects of parameter estimation. Extant candidate functions are reviewed, a role for growth functions such as the Gompertz equation suggested, and a function based on a simple new model outlined. Structurally, the new model comprises a single pool with an inflow and an outflow. Compartmental simulation models based on nonlinear systems of differential equations, and thus requiring numerical solution, are next discussed, and aspects of parameter estimation considered. This type of model is illustrated in relation to development and evaluation of a dynamic model of calcium and phosphorus flows in layers. The model consists of 8 state variables representing calcium and phosphorus pools in the crop, stomachs, plasma, and bone. The flow equations are described by Michaelis-Menten or mass action forms. Experiments that measure Ca and P uptake in layers fed different calcium concentrations during shell-forming days are used to evaluate the model. In addition to providing a useful management tool, such a simulation model also provides a means to evaluate feeding strategies aimed at reducing excretion of potential pollutants in poultry manure to the environment.
    EURRECA—Estimating Zinc Requirements for Deriving Dietary Reference Values
    Lowe, N.M.M. ; Dykes, F.C. ; Skinner, A.L. ; Patel, S. ; Warthon-Medina, M. ; Decsi, T. ; Fekete, K. ; Souverein, O.W. ; Dullemeijer, C. ; Cavelaars, A.J.E.M. ; Serra-Majem, L. ; Nissensohn, M. ; Bel, S. ; Moreno, L.A. ; Hermoso, M. ; Vollhardt, C. ; Berti, C. ; Cetin, I. ; Gurinovic, M. ; Novakovic, R.N. ; Harvey, L.J. ; Collings, R. ; Hall-Moran, V. - \ 2013
    Critical Reviews in Food Science and Nutrition 53 (2013)10. - ISSN 1040-8398 - p. 1110 - 1123.
    current micronutrient recommendations - coronary-artery-disease - lung-cancer - serum zinc - genetic-polymorphism - stable-isotope - old patients - absorption - phytate - copper
    Zinc was selected as a priority micronutrient for EURRECA, because there is significant heterogeneity in the Dietary Reference Values (DRVs) across Europe. In addition, the prevalence of inadequate zinc intakes was thought to be high among all population groups worldwide, and the public health concern is considerable. In accordance with the EURRECA consortium principles and protocols, a series of literature reviews were undertaken in order to develop best practice guidelines for assessing dietary zinc intake and zinc status. These were incorporated into subsequent literature search strategies and protocols for studies investigating the relationships between zinc intake, status and health, as well as studies relating to the factorial approach (including bioavailability) for setting dietary recommendations. EMBASE (Ovid), Cochrane Library CENTRAL, and MEDLINE (Ovid) databases were searched for studies published up to February 2010 and collated into a series of Endnote databases that are available for the use of future DRV panels. Meta-analyses of data extracted from these publications were performed where possible in order to address specific questions relating to factors affecting dietary recommendations. This review has highlighted the need for more high quality studies to address gaps in current knowledge, in particular the continued search for a reliable biomarker of zinc status and the influence of genetic polymorphisms on individual dietary requirements. In addition, there is a need to further develop models of the effect of dietary inhibitors of zinc absorption and their impact on population dietary zinc requirements.
    Role of surface charge in bioavailability and biodistribution of tri-block copolymer nanoparticles in rats after oral exposure
    Bhattacharjee, S. ; Marcelis, A.T.M. ; Zuilhof, H. ; Woutersen, R.A. ; Rietjens, I.M.C.M. ; Alink, G.M. - \ 2013
    Toxicology Research 2 (2013)3. - ISSN 2045-452X - p. 187 - 192.
    silicon nanoparticles - gold nanoparticles - polystyrene particles - fischer-344 rats - cellular uptake - drug-delivery - in-vivo - cytotoxicity - toxicity - absorption
    Tri-block copolymer nanoparticles (TCNP) are increasingly utilized, especially in drug delivery and diagnostics platforms. From in vitro studies, surface charge was observed to influence the transport of TCNP across the Caco-2 monolayers grown on transwell inserts. The objective of this study was to investigate the influence of surface charge on bioavailability and biodistribution of TCNP after oral exposure in vivo and to compare with the in vitro data. To attain the set objectives, monodisperse (45 ± 5 nm), fluorescent and differently charged (positive and negative) TCNP were orally administered to inbred Fischer 344 rats. Blood samples were collected at t = 0, 1/2, 1, 2, 4 and 6 h followed by sacrifice of the animals and collection of the major organs (lungs, liver, kidney, spleen, brain, intestine, and tibia). Quantitative assessments of TCNP in blood and organs were performed by fluorescence measurements. TCNP of both surface charges got absorbed and appeared in the blood within 1/2 h of oral administration. No significant difference in bioavailability and biodistribution could be found between positive and negative TCNP. Both the TCNP, irrespective of charge, showed major accumulation in the liver, kidneys and spleen, were detected in the brain and did not cause any significant increase in the serum alkaline phosphatase levels. Contrary to the in vitro data, surface charge was not found to influence the in vivo bioavailability and biodistribution of TCNP after oral exposure. The obtained results encourage further development of such TCNP, especially for drug delivery purposes.
    Effect of algae- and silt concentration on clearance- and growth rate of the razor clam Ensis directus, Conrad
    Kamermans, P. ; Brummelhuis, E.B.M. ; Dedert, M. - \ 2013
    Journal of Experimental Marine Biology and Ecology 446 (2013). - ISSN 0022-0981 - p. 102 - 109.
    acclimated digestive responses - suspended bottom material - cerastoderma-edule l. - mytilus-edulis - particle selection - feeding bivalves - food quality - absorption - filtration - mussel
    Laboratory experiments were carried out with Ensis directus to estimate clearance rate and growth rate as a function of the amount of food and presence of silt. Two food levels were tested: low food availability (6.5 µg chla/l) and high food availability (16.5 µg chla/l) at four silt concentrations (0, 50, 150 and 300 mg/l). Clearance rates of E. directus varied between 0.7 and 5.9 l/h/g DW. At a silt concentration of 300 mg/l clearance rates were significantly lower (16–56%) than rates at 150 mg/l, 50 mg/l and 0 mg/l silt. This indicates that only the highest silt concentration induced a reduction in clearance rate. The tested food levels did not influence the clearance rate of E. directus. Maximum growth rate of E. directus was 0.24 mm increase in shell length and 2% increase in wet weight per day. Long-term (10 weeks) exposure to silt concentrations of 300 mg/l showed significantly higher growth than the 150 mg/l treatment. This indicates that exposure to a high silt concentration did not induce a reduction in growth, but stimulated growth. Long-term (10 weeks) exposure to a food level of 6.5 µg chla per litre reduced the shell growth of E. directus with 40% compared to growth at 16.5 µg chla per litre. The laboratory experiments suggest that E. directus is more sensitive to a reduction in algal concentration than to an increase in silt concentration.
    Isoenergetic Replacement of Fat by Starch in Diets for African Catfish (Clarias gariepinus): Effect on Water Fluxes in the Gastro Intestinal Tract
    Harter, T.S. ; Verreth, J.A.J. ; Heinsbroek, L.T.N. ; Schrama, J.W. - \ 2013
    PLoS ONE 8 (2013)2. - ISSN 1932-6203
    rainbow-trout - salmo-gairdneri - single meal - in-vivo - absorption - drinking - feed - eels - dry
    The effect of an isoenergetic replacement of dietary fat by starch, on chyme characteristics and water fluxes in the gastro intestinal tract (GIT) was assessed. Adult African catfish (Clarias gariepinus) were fed a starch (SD) or fat (FD) diet and groups of fish were dissected at 2, 5 and 8 h after the consumption of a single meal. Chyme was collected quantitatively and was analysed for osmolality and dry matter (DM) content. Postprandial water fluxes were calculated, while using yttrium oxide (Y2O3) as an inert marker to account for the absorption of DM along the GIT. The largest differences in chyme characteristics between diets were observed in the stomach and decreased towards subsequent compartments. A high initial osmotic pressure was measured in the stomach for both diets (up to 49862 mOsm kg21) and was likely the driver for the endogeneous water influx to this compartment. Large additions of water were recorded to the stomach and proximal intestine for both diets and absorption of water took place in the mid- and distal intestine. Interestingly, the dietary treatment had an impact on water balance in the stomach and proximal intestine of the fish, but not in the mid- and distal intestine. A strong complementary relationship suggested that 59% of the water fluxes in the proximal intestine could be explained by previous additions to the stomach. Therefore, a higher dietary inclusion of starch led to a shift in water additions from the proximal intestine to the stomach. However, the sum of water additions to the GIT was not different between diets and was on average 6.5260.85 ml water g21 DM. The interactions between osmoregulation and digestion, in the GIT of fed freshwater fish, deserve further attention in future research.
    Retrieval of spruce leaf chlorophyll content from airborne image data using continuum removal and radiative transfer
    Malenovsky, Z. ; Homolova, L. ; Zurita-Milla, R. ; Lukes, P. ; Kaplan, V. ; Hanus, J. ; Gastellu-Etchegorry, J.P. ; Schaepman, M.E. - \ 2013
    Remote Sensing of Environment 131 (2013). - ISSN 0034-4257 - p. 85 - 102.
    canopy reflectance models - optical-properties model - area index - hyperspectral data - forest canopies - precision agriculture - vegetation canopies - red - band - absorption
    We investigate combined continuum removal and radiative transfer (RT) modeling to retrieve leaf chlorophyll a & b content (Cab) from the AISA Eagle airborne imaging spectrometer data of sub-meter (0.4 m) spatial resolution. Based on coupled PROSPECT-DART RT simulations of a Norway spruce (Picea abies (L.) Karst.) stand, we propose a new Cab sensitive index located between 650 and 720 nm and termed ANCB650–720. The performance of ANCB650–720 was validated against ground-measured Cab of ten spruce crowns and compared with Cab estimated by a conventional artificial neural network (ANN) trained with continuum removed RT simulations and also by three previously published chlorophyll optical indices: normalized difference between reflectance at 925 and 710 nm (ND925&710), simple reflectance ratio between 750 and 710 nm (SR750/710) and the ratio of TCARI/OSAVI indices. Although all retrieval methods produced visually comparable Cab spatial patterns, the ground validation revealed that the ANCB650–720 and ANN retrievals are more accurate than the other three chlorophyll indices (R2 = 0.72 for both methods). ANCB650–720 estimated Cab with an RMSE = 2.27 µg cm- 2 (relative RRMSE = 4.35%) and ANN with an RMSE = 2.18 µg cm- 2 (RRMSE = 4.18%), while SR750/710 with an RMSE = 4.16 µg cm- 2 (RRMSE = 7.97%), ND925&710 with an RMSE = 9.07 µg cm- 2 (RRMSE = 17.38%) and TCARI/OSAVI with an RMSE = 12.30 µg cm- 2 (RRMSE = 23.56%). Also the systematic RMSES was lower than the unsystematic one only for the ANCB650–720 and ANN retrievals. Our results indicate that the newly proposed index can provide the same accuracy as ANN except for Cab values below 30 µg cm- 2, which are slightly overestimated (RMSE = 2.42 µg cm- 2). The computationally efficient ANCB650–720 retrieval provides accurate high spatial resolution airborne Cab maps, considerable as a suitable reference data for validating satellite-based Cab products.
    Improving the Capture of Co2 by Substituted Monoethanolamines: Electronic Effects of Fluorine and Methyl Substituents
    Gangarapu, S. ; Marcelis, A.T.M. ; Zuilhof, H. - \ 2012
    ChemPhysChem 13 (2012)17. - ISSN 1439-4235 - p. 3973 - 3980.
    main-group thermochemistry - free-energy perturbations - gas-phase basicities - ab-initio - noncovalent interactions - carbon-dioxide - amines - molecules - absorption - accuracy
    The influence of electronic and steric effects on the reaction between CO(2) and monoethanolamine (MEA) absorbents is investigated using computational methods. The pK(a) of the alkanolamine, the reaction enthalpy for carbamate formation, and the hydrolytic carbamate stability are important factors for the efficiency of CO(2) capture. The steric and electronic effects of CH(3), CH(2)F, CHF(2), CF(3), F, dimethyl, difluoro, and bis(2-trifluoromethyl) substituents at the a carbon of MEA on this reaction are investigated. Density functional theory (DFT) (B3LYP, M06-2X, M08-HX and M11-L) and ab initio methods [spin component-scaled second-order Møller-Plesset theory (SCS-MP2), G3], each coupled with solvent models [conductor-like polarizable continuum model (CPCM) and universal solvation models (SM8 and SMD)], are shown to yield accurately calculated pK(a) values of the substituted MEAs. Specifically, G3, SCS-MP2, and M11-L methods coupled with the SMD and SM8 solvation models perform well with a mean unsigned error (MUE) of only 0.15, 0.24 and 0.25 pK(a) units, respectively. SCS-MP2 is used to calculate the reaction enthalpy for carbamate formation and the carbamate stability towards hydrolysis. With the introduction of ß-fluoro substituents (especially the CH(2) F moiety) the reaction enthalpy for the formation of carbamates can be fine-tuned to be less exothermic than that using the unsubstituted MEA. This implies a reduced energy requirement for the solvent-regeneration step in the post-combustion carbon-capture method, which is currently the energy-limiting step in efficient CO(2) capture. ß-Fluoro-substituted MEAs are also shown to form less stable carbamates than MEA. Thus, ß-fluoro-substituted MEAs display a great potential for the use in the post-combustion carbon-capture process. Finally, a clear correlation is observed between the gas-phase basicity and the tendency to form carbamates. This allows for the rapid prediction of which species will be formed experimentally, and thus the CO(2)-absorbing capacities of alkanolamines can be estimated
    Changes in dietary macronutrient profile do not appear to affect endogenous urinary oxalate excretion in healthy adult cats
    Dijcker, J.C. ; Hagen-Plantinga, E.A. ; Hendriks, W.H. - \ 2012
    The Veterinary Journal 194 (2012)2. - ISSN 1090-0233 - p. 235 - 239.
    clinically normal cats - subcellular-distribution - feline uroliths - calcium - glyoxylate - protein - hydroxyproline - canine - metabolism - absorption
    The progressive increase in calcium oxalate uroliths reported in cats diagnosed with urolithiasis may partly be due to changes in nutrition. Since cats have a predominant mitochondrial alanine:glyoxylate aminotransferase 1 (AGT1) location, high carbohydrate intake may induce endogenous oxalate synthesis. This hypothesis was tested by feeding 12 adult, female cats three diets differing in macronutrients, namely, high protein (HP), high carbohydrate (HC) and high fat (HF), using a randomised Latin square design in a 36-day study. In addition to plasma, urine was collected quantitatively using modified litter boxes. A pilot study with four cats, conducted to determine the adaptation time of urinary oxalate (Uox) excretion to a dietary change, indicated a mean (±SEM) adaptation time of 5.9 ± 0.7 days, with the urinary oxalate:creatinine (Ox:Cr) ratio increasing from 36.1 ± 3.7 to 81.6 ± 2.3 mmol/mol. In the main study, plasma oxalate concentration was significantly lower when feeding the HP compared to the HF (P = 0.003) diet, whereas Uox excretion (µmol/kg BW0.75/day) and the urinary Ox:Cr ratio were unaffected by diet. The Uox concentration (mmol/L) was significantly lower when feeding the HP compared to the HC (P = 0.004) and HF (P = 0.001) diets. The results indicate that changes in macronutrient profile may not influence endogenous Uox excretion in cats but high dietary protein did reduce Uox concentration and may therefore help to lower the risk of calcium oxalate formation.
    The relationship between zinc intake and serum/plasma zinc concentration in pregnant and lactating women: A systematic review with dose-response meta-analyses
    Hall Moran, V. ; Skinner, A.L. ; Warthon Medina, M. ; Patel, S. ; Dykes, F. ; Souverein, O.W. ; Dullemeijer, C. ; Lowe, N.M.M. - \ 2012
    Journal of Trace Elements in Medicine and Biology 26 (2012)2-3. - ISSN 0946-672X - p. 74 - 79.
    mexican descent - plasma zinc - milk zinc - supplementation - iron - metabolism - absorption - serum
    Recommendations for zinc intake during pregnancy and lactation vary widely across Europe. Using data on zinc intake and biomarkers of zinc status reported in randomized controlled trials (RCTs) and observational studies can provide estimates of dose–response relationships that may be used for underpinning zinc reference values. This systematic review included all RCTs, prospective cohort studies, nested case–control studies and cross-sectional studies in healthy pregnant and lactating populations published by February 2010 which provided data on zinc intake and biomarkers of zinc status. An intake-status regression coefficient was calculated for each individual study and calculated the overall pooled and SE using random effects meta-analysis on a double log scale. The pooled dose–response relationship between zinc intake and zinc status found that a doubling of zinc intake was associated with an increase in serum/plasma zinc status by 3% in pregnant women and by 1% in lactating women. These modest associations are likely to reflect the low-moderate zinc bioavailability dietary patterns and the widespread use of other micronutrients in the populations included in this review, physiologic adjustments of zinc homeostasis, insensitivity of serum/plasma zinc as a biomarker of zinc status, and wide heterogeneity between study results which reflect real uncertainty in the current evidence base. Although this review provides useful information for dietary zinc requirements in populations vulnerable to zinc deficiency, it also highlights a need for further studies in pregnant and lactating women with different dietary patterns in order to provide useful complementary evidence that can be utilized when setting zinc recommendations as a basis for nutrition policies in Europe.
    Presence of Nano-Sized Silica during In Vitro Digestion of Foods Containing Silica as a Food Additive
    Peters, R.J.B. ; Kramer, E.H.M. ; Oomen, A.G. ; Rivera, Z.H. ; Oegema, G. ; Tromp, P.C. ; Fokkink, R.G. ; Rietveld, A. ; Marvin, H.J.P. ; Weigel, S. ; Peijnenburg, A.A.C.M. ; Bouwmeester, H. - \ 2012
    ACS Nano 6 (2012)3. - ISSN 1936-0851 - p. 2441 - 2451.
    gastrointestinal uptake - particle-size - bioaccessibility - model - contaminants - absorption - hazard
    The presence, dissolution, agglomeration state, and release of materials in the nano-size range from food containing engineered nanoparticles during human digestion is a key question for the safety assessment of these materials. We used an in vitro model to mimic the human digestion. Food products subjected to in vitro digestion included (i) hot water, (ii) coffee with powdered creamer, (iii) instant soup, and (iv) pancake which either contained silica as the food additive E551, or to which a form of synthetic amorphous silica or 32 nm SiO2 particles were added. The results showed that, in the mouth stage of the digestion, nano-sized silica particles with a size range of 5–50 and 50–500 nm were present in food products containing E551 or added synthetic amorphous silica. However, during the successive gastric digestion stage, this nano-sized silica was no longer present for the food matrices coffee and instant soup, while low amounts were found for pancakes. Additional experiments showed that the absence of nano-sized silica in the gastric stage can be contributed to an effect of low pH combined with high electrolyte concentrations in the gastric digestion stage. Large silica agglomerates are formed under these conditions as determined by DLS and SEM experiments and explained theoretically by the extended DLVO theory. Importantly, in the subsequent intestinal digestion stage, the nano-sized silica particles reappeared again, even in amounts higher than in the saliva (mouth) digestion stage. These findings suggest that, upon consumption of foods containing E551, the gut epithelium is most likely exposed to nano-sized silica.
    Phytic Acid-to-Iron Molar Ratio Rather than Polyphenol Concentration Determines Iron Bioavailability in Whole-Cowpea Meal among Young Women
    Abizari, A.R. ; Moretti, D. ; Zimmerman, M.B. ; Armar-Klemesu, M. ; Brouwer, I.D. - \ 2012
    The Journal of Nutrition 142 (2012)11. - ISSN 0022-3166 - p. 1950 - 1955.
    sodium-bicarbonate - phaseolus-vulgaris - absorption - isotope - food - fortification - phytate - humans - beans - availability
    Limited data exist on iron absorption from NaFeEDTA and FeSO(4) in legume-based flours. The current study compared iron absorption from NaFeEDTA and FeSO(4) as fortificants within and between red and white varieties of cowpea with different concentrations of polyphenols (PP) but similar phytic acid (PA)-to-iron molar ratios. We performed a paired crossover study in young women (n = 16). Red-cowpea (high-PP) and white-cowpea (low-PP) test meals (Tubani) were each fortified with ((57)Fe)-labeled NaFeEDTA or ((58)Fe)-labeled FeSO(4) and were randomly administered. Iron absorption was measured as erythrocyte incorporation of stable iron isotopes. Per serving, the mean (±SD) PP concentrations of the white- and red-cowpea-based meals were 74 ± 3.6 and 158 ± 1.8 mg, respectively, and the molar ratio of PA to iron was 3.0 and 3.3. Iron bioavailabilities from red and white cowpeas were 1.4 and 1.7%, respectively, in NaFeEDTA-fortified meals and 0.89 and 1.2%, respectively, in FeSO(4)-fortified meals. Compared with FeSO(4), fortification with NaFeEDTA increased the amount of iron absorbed from either of the cowpea meals by 0.05 to 0.08 mg (P <0.05). Irrespective of the fortificant used, there was no significant difference in the amount of iron absorbed from the 2 varieties of cowpea. The results suggest that NaFeEDTA is more bioavailable in legume-based flours compared with FeSO(4). In cowpea-based flours, the major determinant of low iron absorption may be the high molar ratio of PA to iron and not variations in PP concentration
    Root water uptake as simulated by three water flow models
    Willigen, P. de; Dam, J.C. van; Javaux, M. ; Heinen, M. - \ 2012
    Vadose Zone Journal 11 (2012)3. - ISSN 1539-1663 - 14 p.
    flux potential approach - hydraulic conductivity - integrated approach - nutrient-uptake - architecture - system - absorption - scales - maize
    The objective of our study was to determine to what extent four root water uptake (RWU) models differed when tested under extreme conditions. Cumulative transpiration patterns were similar, contrary to the spatial extraction patterns. The analysis showed that both soil physical and root physiological factors are important for proper deterministic modeling of RWU. We compared four root water uptake (RWU) models of different complexity that are all embedded in greater soil water flow models. The soil models used were SWAP (one-dimensional), FUSSIM2 (two-dimensional), and RSWMS (three-dimensional). Within SWAP, two RWU functions were utilized (SWAP-macro and SWAP-micro). The complexity of the processes considered in RWU increases from SWAP-macro, to SWAP-micro, to FUSSIM2, to RSWMS. The objective of our study was to determine to what extent the RWU models differed when tested under extreme conditions: low root length density, high transpiration rate, and low water content. Comparison 1 looked at the results of the models for a scenario of transpiration and uptake and Comparison 2 studied compensation mechanisms of water uptake. The uptake scenario pertained to a long dry period with constant transpiration and a single rainfall event. As could be expected, the models yielded different results in Comparison 1, but the differences in cumulative transpiration were modest due to various feedback mechanisms. In Comparison 2, the cumulative effect of different feedback processes were studied. Redistribution of water due to soil pressure head gradients generated by water uptake led to an increase in cumulative transpiration of 32%, and the inclusion of compensation in uptake by the roots resulted in a further increase of 10%. Going from one- to three-dimensional modeling, the horizontal gradients in the soil and root system increased, which reduced the actual transpiration. The analysis showed that both soil physical and root physiological factors are important for proper deterministic modeling of RWU
    In vitro study of intestinal lipolysis using pH-stat and gas chromatography
    Helbig, A. ; Silletti, E. ; Timmerman, E. ; Hamer, R.J. ; Gruppen, H. - \ 2012
    Food Hydrocolloids 28 (2012)1. - ISSN 0268-005X - p. 10 - 19.
    pancreatic lipase activity - human gastric lipase - fat digestion - bile-salt - stereoselective hydrolysis - emulsion flocculation - droplet sizes - digestibility - triglycerides - absorption
    Developing healthy products requires in-depth knowledge of digestion. This study focuses on lipid digestion in relation to emulsion properties typically followed by pH-stat. Although this is a fast and easy method to follow the overall digestion, it provides no details on lipid digestion products. Thus, the aims of the present study were to use gas chromatography (GC) to determine all products present during lipolysis, i.e. monoglycerides (MG), diglycerides (DG) and triglycerides (TG), and to compare this method with the pH-stat method for free fatty acids (FFA). Fine, medium and coarse emulsions stabilized with two different emulsifiers (whey protein isolate (WPI) or gum arabic) were digested under in vitro intestinal conditions. Although the amount of FFA increased for both methods for WPI stabilized emulsions, the amount of FFA was 2–3 times higher when determined by GC compared with pH-stat. GC analysis showed decreasing amounts of MG and DG with increasing droplet size for both emulsions. Molar ratios of FFA/DG and MG/DG were twofold higher for WPI than for gum arabic stabilized emulsions. This indicates that the total production of lipolytic products (i.e. FFA + MG + DG) depends on the droplet size and the emulsifier but their proportions only depend on the emulsifier. Although pH-stat provides a fast measure of FFA release, it is influenced by the emulsifier type at the oil–water interface and therefore care should be taken when interpreting pH-stat results. We suggest combining this method with GC for accurate FFA determination and further evaluation of all lipolytic products.
    Selenium status in adult cats and dogs fed high levels of dietary inorganic and organic selenium
    Todd, S.E. ; Thomas, D.G. ; Bosch, G. ; Hendriks, W.H. - \ 2012
    Journal of Animal Science 90 (2012)8. - ISSN 0021-8812 - p. 2549 - 2555.
    brush-border membrane - pet foods - absorption - selenate - liver - rat - se
    Cats maintain higher blood Se concentrations compared to dogs and, unlike dogs, show no signs of chronic Se toxicity (selenosis) when fed dietary organic Se (selenomethionine) concentrations of 10 µg/g DM. This study investigated the response of cats and dogs to high dietary concentrations of sodium selenite and organic Se to determine differences in metabolism between both species. In 2 consecutive studies, 18 adult cats and 18 adult dogs of equal sex were fed a control diet (0.6 µg Se/g DM) or the control diet supplemented to 8 to 10 µg Se/g DM from Na2SeO3 or organic Se for 3 wk. All animals were fed the control diet 1 mo before the start of the study and blood samples were taken on d 0 and 21. The Se balance was assessed during the final week and a liver biopsy was obtained on the final day of the study. Measurements included plasma Se concentrations, plasma glutathione peroxidise (GPx) activities, plasma Se clearance, Se intake, and urinary Se excretion. No clinical signs of selenosis were observed in the cats or dogs, and apart from Se clearance, form of Se had no effect on any of the measurements. Apparent fecal Se absorption was greater in the dogs fed both forms of Se, while greater plasma Se concentrations were observed in the cats on both the control and supplemented diet (P = 0.034). Cats fed the supplemented diets had lower hepatic Se concentrations (P <0.001) and excreted more Se in urine (P <0.001) compared to dogs. Furthermore, cats fed the Na2SeO3 supplement had greater Se clearance rates than dogs (P <0.001). There was no effect of species on plasma GPx activity. We conclude that cats can tolerate higher dietary Se concentrations as they are more efficient at excreting excess Se in the urine and storing less Se in the liver
    Hepcidin is the major predictor of erythrocyte iron incorporation in anemic African children
    Prentice, A.M. ; Doherty, C.P. ; Abrams, S.A. ; Cox, S.E. ; Atkinson, S.H. ; Verhoef, J.C.M. ; Armitage, A.E. ; Drakesmith, H. - \ 2012
    Blood : journal of the American Society of Hematology 119 (2012)8. - ISSN 0006-4971 - p. 1922 - 1928.
    serum hepcidin - plasmodium-falciparum - malarial anemia - absorption - infection - inflammation - deficiency - metabolism - erythropoiesis - hypoferremia
    Iron supplementation strategies in the developing world remain controversial because of fears of exacerbating prevalent infectious diseases. Understanding the conditions in which iron will be absorbed and incorporated into erythrocytes is therefore important. We studied Gambian children with either postmalarial or nonmalarial anemia, who were given oral iron supplements daily for 30 days. Supplements administered on days 1 and 15 contained the stable iron isotopes 57Fe and 58Fe, respectively, and erythrocyte incorporation was measured in blood samples drawn 14 days later. We investigated how the iron-regulatory hormone hepcidin and other inflammatory/iron-related indices, all measured on the day of isotope administration, correlated with erythrocyte iron incorporation. In univariate analyses, hepcidin, ferritin, C-reactive protein, and soluble transferrin receptor (sTfR) strongly predicted incorporation of 57Fe given on day 1, while hepcidin, ferritin, and sTfR/log ferritin correlated with 58Fe incorporation. In a final multivariate model, the most consistent predictor of erythrocyte isotope incorporation was hepcidin. We conclude that under conditions of competing signals (anemia, iron deficiency, and infection), hepcidin powerfully controls use of dietary iron. We suggest that low-cost point-of-care hepcidin assays would aid iron supplementation programs in the developing world.
    Variation in rumen fermentation and the rumen wall during the transition period in dairy cows
    Bannink, A. ; Gerrits, W.J.J. ; France, J. ; Dijkstra, J. - \ 2012
    Animal Feed Science and Technology 172 (2012)1-2. - ISSN 0377-8401 - p. 80 - 94.
    subacute ruminal acidosis - chain fatty-acids - veal calf diets - early lactation - carbohydrate-composition - metabolic disorders - absorption - ph - adaptation - sodium
    Strong adaptive changes occur in the peri-parturient dairy cow related to a marked rise in dry matter intake and alteration in diet composition after calving. Early lactation dairy cattle are susceptible to metabolic disorders and impaired rumen function during the transition period, with detrimental effects on cow performance. For a quantitative understanding of the dietary effects on rumen function, several classes of influencing factors can be distinguished (intrinsic degradation characteristics of feed, characteristics of microbial activity, rumen fermentation conditions, rumen wall function). Interpretation of experimental results requires all these factors to be taken into consideration simultaneously. This contribution aimed to review the capacity of the rumen wall to adapt to the marked increase in feed intake by the post-parturient dairy cow. While the principle of distinct adaptations of the post-parturient rumen wall is generally accepted, literature is not always conclusive about the size of the effects. Virtually all studies on adaptation of the post-parturient rumen wall were performed post-mortem and with isolated tissue in vitro. Therefore, an in vivo trial with twelve rumen fistulated dairy cows is presented to support and discuss the various factors involved in this review. A faster (in 10 d) versus a slower (in 20 d) increment of starch-rich concentrate intake after calving was evaluated for effects on adaptive response of rumen epithelia and altered rumen functioning up to twelve weeks after calving. Results showed transient changes in rumen epithelia and suggest a different adaptive response of rumen epithelia during the first weeks of lactation due to differences in supplemental concentrate feeding. No evidence was found for any detrimental effect of a fast increment of concentrate intake on dry matter intake, rumen fermentation, and cow performance. Results in literature either confirm or contradict these findings, and they attribute either a more important role to molecular mechanisms in rumen epithelia or to cell proliferation and epithelial morphology. The different research methods adopted and the high variability of results obtained with this type of research strongly limit our understanding of the relative importance of cell metabolic changes, epithelia proliferation and rumen wall morphology. In conclusion, the ruminal epithelia in the peri-parturient cow responds in a coordinated manner to rapid dietary changes which is of high significance to maintain normal rumen function
    Apple extract induces increased epithelial resistance and claudin 4 expression in Caco-2 cells
    Vreeburg, R.A.M. ; Wezel, E.E. van; Ocana-Calahorro, F. ; Mes, J.J. - \ 2012
    Journal of the Science of Food and Agriculture 92 (2012)2. - ISSN 0022-5142 - p. 439 - 444.
    tight junction permeability - intestinal barrier function - in-vitro - disease - absorption - mechanisms - monolayer - kinase
    BACKGROUND: The small intestinal epithelium functions both to absorb nutrients, and to provide a barrier between the outside, luminal, world and the human body. One of the passageways across the intestinal epithelium is paracellular diffusion, which is controlled by the properties of tight junction complexes. We used a differentiated Caco-2 monolayer as a model for small intestinal epithelium to study the effect of crude apple extracts on paracellular permeability. RESULTS: Exposure of crude apple homogenate to the differentiated Caco-2 cells increased the paracellular resistance, determined as trans-epithelial electrical resistance (TEER). This increase was linearly related to the concentration of apple present. The TEER-enhancing effect of apple extract was due to factors mainly present in the cortex, and the induction was not inhibited by protein kinase inhibitors. Apple-induced resistance was accompanied by increased expression of several tight junction related genes, including claudin 4 (CLDN4). CONCLUSION: Crude apple extract induces a higher paracellular resistance in differentiated Caco-2 cells. Future research will determine whether these results can be extrapolated to human small intestinal epithelia
    Colonization-Induced Host-Gut Microbial Metabolic Interaction
    Claus, S.P. ; Ellero, S.L. ; Berger, B. ; Krause, L. ; Bruttin, A. ; Molina, J. ; Paris, A. ; Want, E.J. ; Waziers, I. de; Cloarec, O. ; Richards, S.E. ; Wang, Y. ; Dumas, M.E. ; Ross, A. ; Rezzi, S. ; Kochhar, S. ; Bladeren, P.J. van; LindOn, J.C. ; Holmes, E. ; Nicholson, J.K. - \ 2011
    mBio 2 (2011)2. - ISSN 2150-7511 - 8 p.
    diet-induced obesity - bile-acids - absorption - liver - mice - rat - cholesterol - bacteria - energy - flora
    The gut microbiota enhances the host’s metabolic capacity for processing nutrients and drugs and modulate the activities of multiple pathways in a variety of organ systems. We have probed the systemic metabolic adaptation to gut colonization for 20 days following exposure of axenic mice (n = 35) to a typical environmental microbial background using high-resolution 1H nuclear magnetic resonance (NMR) spectroscopy to analyze urine, plasma, liver, kidney, and colon (5 time points) metabolic profiles. Acquisition of the gut microbiota was associated with rapid increase in body weight (4%) over the first 5 days of colonization with parallel changes in multiple pathways in all compartments analyzed. The colonization process stimulated glycogenesis in the liver prior to triggering increases in hepatic triglyceride synthesis. These changes were associated with modifications of hepatic Cyp8b1 expression and the subsequent alteration of bile acid metabolites, including taurocholate and tauromuricholate, which are essential regulators of lipid absorption. Expression and activity of major drug-metabolizing enzymes (Cyp3a11 and Cyp2c29) were also significantly stimulated. Remarkably, statistical modeling of the interactions between hepatic metabolic profiles and microbial composition analyzed by 16S rRNA gene pyrosequencing revealed strong associations of the Coriobacteriaceae family with both the hepatic triglyceride, glucose, and glycogen levels and the metabolism of xenobiotics. These data demonstrate the importance of microbial activity in metabolic phenotype development, indicating that microbiota manipulation is a useful tool for beneficially modulating xenobiotic metabolism and pharmacokinetics in personalized health care.
    Fortification Iron as Ferrous Sulfate Plus Ascorbic Acid Is More Rapidly Absorbed Than as Sodium Iron EDTA but Neither Increases Serum Nontransferrin-Bound Iron in Women
    Troesch, B. ; Egli, I. ; Zeder, C. ; Hurrell, R.F. ; Zimmermann, M.B. - \ 2011
    The Journal of Nutrition 141 (2011)5. - ISSN 0022-3166 - p. 822 - 827.
    double stable-isotope - ethylenediaminetetraacetic acid - revised recommendations - breakfast meal - healthy women - absorption - plasma - transferrin - infants - quantification
    The absorption profile of iron fortificants may be a determinant of their ability to generate nontransferrin-bound iron (NTBI) and, thus, their potential safety. Ferrous iron may be absorbed more rapidly than chelated ferric iron, but differences at the fortification level cannot be distinguished with nonisotopically labeled serum iron curves. Using stable isotope appearance curves (SIAC) in serum, we measured iron absorption profiles from FeSO(4) with ascorbic acid (AA) and from NaFeEDTA, as well as the serum hepcidin and NTBI response following the meals. Healthy women (n = 16) were given 6 mg oral iron as labeled FeSO(4) and NaFeEDTA with a maize porridge using a crossover design. SIAC, NTBI, and serum hepcidin were measured over 8 h after the meal. Iron from FeSO(4) plus AA was more rapidly absorbed, resulting in a 35% greater relative AUC during the first 2 h than for NaFeEDTA (P <0.001). Median (95% CI) fractional iron absorption from the FeSO(4)- and NaFeEDTA-fortified meals was 15.2% (11.0-19.5) and 6.0% (5.0-9.2), respectively (P <0.001). In response to the FeSO(4)-fortified meal, here was an similar to 60% increase in median serum hepcidin (P <0.05) but no significant change in NTBI. There was no significant change in serum hepcidin or NTBI after the NaFeEDTA-fortified meal. SIAC are a useful new tool to compare iron absorption profiles from different iron compounds in fortified foods. Even with the use of a very well absorbed ferrous iron compound, iron fortification in this population does not increase NTBI, suggesting a low risk for adverse health consequences. J. Nutr. 141: 822-827, 2011.
    Phytase activity in brown rice during steeping and sprouting
    Ou, K. ; Cheng, Y. ; Xing, Y. ; Lin, L. ; Nout, M.J.R. ; Liang, J. - \ 2011
    Journal of Food Science and Technology-Mysore 48 (2011)5. - ISSN 0022-1155 - p. 598 - 603.
    phytic acid content - inositol phosphates - germination - phosphorus - soaking - purification - absorption - wheat - seeds - zinc
    Phytase in brown rice will be activated and accumulated during seed germination. Changes of phytase activity in brown rice during two stages of germination (steeping and sprouting) affected by process conditions were studied. It was shown that steeping led to significant decrease of phytase activity (p¿
    An attempt to define the sodium requirements of lactating dairy cows in a tropical environment
    Thiangtum, W. ; Yawongsa, A. ; Schonewille, J.T. ; Rukkwamsuk, T. ; Yuangklang, C. ; Verstegen, M.W.A. ; Hendriks, W.H. - \ 2011
    Journal of the Science of Food and Agriculture 91 (2011)13. - ISSN 0022-5142 - p. 2333 - 2337.
    acid-base status - potassium-chloride - mineral metabolism - dietary-sodium - heat-stress - responses - supplementation - magnesium - bicarbonate - absorption
    BACKGROUND: Lactating dairy cattle in the tropics may require more sodium (Na) owing to the hot and humid climatic conditions. It is unknown whether the current recommendations on Na for lactating cows can be quantitatively used in tropical countries. This study attempted to define the Na requirement of lactating dairy cows under tropical conditions by measuring Na levels in saliva, milk and faeces. RESULTS: The concentrations of Na and potassium (K) in milk, faeces and serum were not affected by dietary treatments. The amount of Na absorbed by cows fed the basal (low-Na) diet containing 0.4 g Na kg-1 dry matter (DM) was equal to the amount of Na lost in the milk, showing that these animals were fed an Na-deficient ration. This observation was corroborated by salivary Na and K levels, with the cows on the low-Na diet having salivary Na concentrations below 120 mmol L-1 in combination with salivary K concentrations above 20 mmol L-1 (P <0.05). CONCLUSION: Consumption of a daily ration formulated to contain the current Na requirement set by the NRC appears to provide too much Na for lactating cows under tropical conditions. A tentative value of 1.2 g kg-1 DM is proposed as the Na requirement for dairy cows under tropical conditions. Copyright © 2011 Society of Chemical Industry
    Interaction of hesperetin glucuronide conjugates with human BCRP, MRP2 and MRP3 as detected in membrane vesicles of overexpressing baculovirus-infected Sf9 cells
    Brand, W. ; Oosterhuis, B. ; Krajcsi, P. ; Barron, D. ; Dionisi, F. ; Bladeren, P.J. van; Rietjens, I. ; Williamson, G. - \ 2011
    Biopharmaceutics and Drug Disposition 32 (2011)9. - ISSN 0142-2782 - p. 530 - 535.
    phase-ii metabolism - disposition - monolayers - hesperidin - bioavailability - transporters - absorption - flavanones - flavonoids - fruit
    The citrus flavonoid hesperetin (4'-methoxy-3',5,7-trihydroxyflavanone) is the aglycone of hesperidin, the major flavonoid present in sweet oranges. Hesperetin 7-O-glucuronide (H7G) and hesperetin 3'-O-glucuronide (H3'G) are the two most abundant metabolites of hesperetin in vivo. In this study, their interaction with specific ABC transporters, believed to play a role in the disposition and bioavailability of hesperetin, was studied using Sf9 membranes from cells overexpressing human BCRP (ABCG2), MRP2 (ABCC2) and MRP3 (ABCC3). Both H7G and H3'G were tested for their potential to activate and inhibit ATPase activity, and to inhibit vesicular transport by these transporters. Both H7G and H3'G demonstrated interaction with all tested ABC transporters, especially with BCRP and MRP3. An interesting difference between H7G and H3'G was seen with respect to the interaction with BCRP: H7G stimulated the ATPase activity of BCRP up to 76% of the maximal effect generated by the reference activator sulfasalazine, with an EC(50) of 0.45¿µ m, suggesting that H7G is a high affinity substrate of BCRP, whereas H3'G did not stimulate BCRP ATPase activity. Only moderate inhibition of BCRP ATPase activity at high H3'G concentrations was observed. This study provides information on the potential of hesperetin glucuronide conjugates to act as specific ABC transporter substrates or inhibitors and indicates that regio-specific glucuronidation could affect the disposition of hesperetin.
    A model of enteric fermentation in dairy cows to estimate methane emission for the Dutch National Inventory Report using the IPCC Tier 3 approach
    Bannink, A. ; Schijndel, M.W. van; Dijkstra, J. - \ 2011
    Animal Feed Science and Technology 166-167 (2011). - ISSN 0377-8401 - p. 603 - 618.
    volatile fatty-acids - mechanistic rumen models - lactating cows - nutrient digestion - prediction - absorption - simulation - ph - netherlands - parameters
    The protocol for the National Inventory of agricultural greenhouse gas emissions in The Netherlands includes a dynamic and mechanistic model of animal digestion and fermentation as an Intergovernmental Panel on Climate Change (IPCC) Tier 3 approach to estimate enteric CH4 emission by dairy cows. The model differs from an IPCC Tier 2 approach in that it predicts hydrogen sources (i.e., production of acetate and butyrate, microbial growth on amino acids as an N source) and sinks (i.e., production of propionate and the remainder of the volatile fatty acids (VFA), microbial growth on ammonia as an N source, saturation of unsaturated long chain fatty acids) in the rumen and large intestine, and elimination of excess hydrogen by methanogenesis. As a result, the model predicts CH4 emission by considering various dietary characteristics, including the types of carbohydrate, protein, fat, intrinsic degradation characteristics of feeds, as well as ruminal fractional passage rates, fluid volume and acidity, instead of assuming a fixed CH4 energy conversion factor in the Tier 2 approach. Annual statistics of diet and performance of the average dairy cow in The Netherlands from 1990 until 2008 indicate that dry matter intake and yield of fat and crude protein corrected milk (FPCM) per cow/year increased by 20 and 34% respectively. Based on annual data for diet and FPCM, the model predicted an increase in enteric CH4 emission from 111 (1990) to 128 (2008) kg/cow/year. As a result, CH4 emission per kg FPCM milk decreased by 13%. The predicted fraction of gross energy intake lost as CH4 energy gradually declined and was close to 0.06, which is the IPCC (1997) Tier 2 default value of 0.06 for dairy cows, but ~10% lower than the IPCC (2006) updated value of 0.065. The 15% uncertainty value for predicted CH4 emissions for a reference diet was lower than the 20% assumed under Tier 2. Our analysis indicated that uncertainty of model predictions of CH4 emission is determined mostly by errors in feed intake estimation, in the representation of the stoichiometry of production of VFA from fermented substrate, and in the acidity of rumen contents. Further uncertainty of predicted CH4 emission was due to errors in estimation of dietary composition of ingredients and in chemical compositions of dietary components. Results demonstrate that prediction of CH4 should not solely focus on representing effects of nutrition on overall digestion and apparent feed utilization by cows, but that additional attention is needed to address effects of nutrition on intra-ruminal fermentation conditions, and their effects on formation of VFA and the rumen hydrogen balance.
    Trpv5/6 is vital for epithelial calcium uptake and bone formation
    Vanoevelen, J. ; Janssens, A. ; Huitema, L.F.A. ; Hammond, C.L. ; Metz, J.R. ; Flik, G. ; Voets, T. ; Schulte-Merker, S. - \ 2011
    FASEB Journal 25 (2011)9. - ISSN 0892-6638 - p. 3197 - 3207.
    ca2+ channel - in-vivo - stannius corpuscles - cation channels - stanniocalcin 1 - danio-rerio - absorption - zebrafish - transport - receptor
    Calcium is an essential ion serving a multitude of physiological roles. Aside from its role as a second messenger, it is an essential component of the vertebrate bone matrix. Efficient uptake and storage of calcium are therefore indispensable for all vertebrates. Transient receptor potential family, vanilloid type (TRPV)5 and TRPV6 channels are known players in transcellular calcium uptake, but the exact contribution of this pathway is unclear. We used forward genetic screening in zebrafish (Danio rerio) to identify genes essential in bone formation and identified a lethal zebrafish mutant (matt-und-schlapp) with severe defects in bone formation, including lack of ossification of the vertebral column and craniofacial structures. Mutant embryos show a 68% reduction in calcium content, and systemic calcium homeostasis is disturbed when compared with siblings. The phenotype can be partially rescued by increasing ambient calcium levels to 25 mM. We identified the mutation as a loss-of-function mutation in the single orthologue of TRPV5 and 6, trpv5/6. Expression in HEK293 cells showed that Trpv5/6 is a calcium-selective channel capable of inward calcium transport at physiological concentrations whereas the mutant channel is not. Taken together, this study provides both genetic and functional evidence that transcellular epithelial calcium uptake is vital to sustain life and enable bone formation.—Vanoevelen, J., Janssens, A., Huitema, L. F. A., Hammond, C. L., Metz, J. R., Flik, G., Voets, T., Schulte-Merker, S. Trpv5/6 is vital for epithelial calcium uptake and bone formation
    Weight status and iron deficiency among urban Malian women of reproductive age
    Fanou-Fogny, N.M.L. ; Saronga, N.J. ; Koreissi, Y. ; Dossa, R.A.M. ; Boonstra, A. ; Brouwer, I.D. - \ 2011
    The British journal of nutrition 105 (2011)4. - ISSN 0007-1145 - p. 574 - 579.
    obesity - absorption - hepcidin - overweight - hypoferremia - inflammation - transition - expression - children
    The present study investigated the association between weight status and Fe deficiency (ID) among urban Malian women of reproductive age. Height, weight, serum ferritin (SF), soluble transferrin receptor (sTfR) and C-reactive protein (CRP) concentrations were measured in sixty apparently healthy women aged 15-49 years old in Bamako, Mali. Prevalences of overweight and obese were 19 and 9%, respectively. SF was non-significantly different between overweight (84 mu g/l) and normal-weight women (52 mu g/l). The prevalence of ID (SF <12 mu g/l) was 9% in the overweight group and no true ID (sTfR > 8.3 mg/l) cases were recorded in the overweight and obese groups. The prevalence OR of ID (SF <12 mu g/l) in the overweight group was NS (OR = 0.3; P=0.363). Conversely, the chronic energy deficiency group was at a significantly higher risk of ID than the normal-weight group, adjusting or not for CRP (OR = 7.7; 95% CI 1.49, 39.96; P=0.015). The lack of association between overweight and ID in the present study could be due to the fact that the excess of body fat of the women might not be critical to induce chronic inflammation related to reduced Fe absorption. Future research based on a larger convenience sample should be designed to further investigate associations between overweight, obesity and ID in developing countries.
    Estimating specific inherent optical properties of tropical coastal waters using bio-optical model inversion and in situ measurements: case of the Berau estuary, East Kalimantan, Indonesia
    Ambarwulan, W. ; Salama, M.S. ; Mannaerts, C.M. ; Verhoef, W. - \ 2011
    Hydrobiologia 658 (2011)1. - ISSN 0018-8158 - p. 197 - 211.
    dissolved organic-matter - ocean color - scattering coefficients - absorption - chlorophyll - phytoplankton - seawifs - reflectance - throughflow - variability
    Specific inherent optical properties (SIOP) of the Berau coastal waters were derived from in situ measurements and inversion of an ocean color model. Field measurements of water-leaving reflectance, total suspended matter (TSM), and chlorophyll a (Chl a) concentrations were carried out during the 2007 dry season. The highest values for SIOP were found in the turbid waters, decreasing in value when moving toward offshore waters. The specific backscattering coefficient of TSM varied by an order of magnitude and ranged from 0.003 m2 g-1, for clear open ocean waters, to 0.020 m2 g-1, for turbid waters. On the other hand, the specific absorption coefficient of Chl a was relatively constant over the whole study area and ranged from 0.022 m2 mg-1, for the turbid shallow estuary waters, to 0.027 m2 mg-1, for deeper shelf edge ocean waters. The spectral slope of colored dissolved organic matter light absorption was also derived with values ranging from 0.015 to 0.011 nm-1. These original derived values of SIOP in the Berau estuary form a corner stone for future estimation of TSM and Chl a concentration from remote sensing data in tropical equatorial waters
    Random serial sampling to evaluate efficacy of iron fortification: a randomized controlled trial of margarine fortification with ferric pyrophosphate or sodium iron edetate 1-3
    Andersson, M. ; Theis, W. ; Zimmermann, M.B. ; Forman, J.T. ; Jakel, M. ; Duchateau, G.S.M.J.E. ; Frenken, L.G.J. ; Hurrell, R.F. - \ 2010
    American Journal of Clinical Nutrition 92 (2010)5. - ISSN 0002-9165 - p. 1094 - 1104.
    population pharmacokinetics - relative bioavailability - double-blind - transferrin receptor - dual fortification - whole diet - deficiency - absorption - iodine - salt
    Background: Random serial sampling is widely used in population pharmacokinetic studies and may have advantages compared with conventional fixed time-point evaluation of iron fortification. Objective: Our objective was to validate random serial sampling to judge the efficacy of iron fortification of a low-fat margarine. Design: We conducted a 32-wk placebo-controlled, double-blind, iron-intervention trial in 18–40-y-old Swiss women (n = 142) with serum ferritin (SF) concentrations
    Dietary non-heme iron bioavailability among children (5-8 years) in a rural, high anemia prevalent area in North India: comparison of algorithms.
    Rani, V.R. ; Trijsburg, L. ; Brouwer, I.D. ; Khetarpaul, N. - \ 2010
    Ecology of Food and Nutrition 49 (2010)4. - ISSN 0367-0244 - p. 262 - 278.
    absorption - prediction - agreement - foods - women
    Non-heme iron bioavailability of diet consumed by children (ages 5 to 8) in rural area of India was estimated by comparison of algorithms. A cross-sectional observational study was conducted among 232 children and consisted of a 24-hour recall on 2 nonconsecutive days. Four algorithms were chosen to estimate the non-heme iron bioavailability. Daily average non-heme iron bioavailability as calculated by different algorithms was low (between 3.2% and 4.6%). Correlations of bioavailable non-heme iron among different algorithms were strong, ranging from rs = 0.67 to rs = 0.85 (p = .01)
    Urinary calcium excretion in non-lactating dairy cows in relation to intake of fat-coated rice bran
    Martin-Tereso, J. ; Derks, M. ; Laar, H. van; Mulder, K. ; Hartog, L.A. den; Verstegen, M.W.A. - \ 2010
    Journal of Animal Physiology and Animal Nutrition 94 (2010)1. - ISSN 0931-2439 - p. 129 - 136.
    cation-anion difference - milk fever - dry period - gastrointestinal-tract - parturient paresis - hypocalcemia - absorption - magnesium - supplementation - phosphorus
    At calving, many older cows fail to compensate the sudden demand of calcium by an adequate activation of intestinal absorption. This results in a variable degree of hypocalcaemia. Reducing intestinal availability of calcium during the close-up period can prevent milk fever. Fat-coated rice bran (FCRB) was investigated for its potential to reduce Ca availability in pre-calving cows. Fat-coated rice bran was incubated in situ to estimate ruminal degradation of dry matter and phytic acid. Also, seven dry multiparous dairy cows were used for a feeding trial in three periods of approximately 1 week each: P1: adaptation; P2: feeding of 2 kg of FCRB and P3: withdrawal of FCRB. Feed intake was recorded and daily urine samples were analysed for pH, Ca and creatinine. The bypass fraction of phytic acid (passage rate: 5%/h) was 30%. Fat-coated rice bran depressed dry matter intake in P2, resulting in a lower Ca intake. In P2 urine pH and calcium excretion were lower. Daily calcium excretion decreased after introduction of FCRB, peaked after withdrawal and dropped 2 days later. Changes in urinary Ca excretion by feeding FCRB indicate that FCRB affected Ca homeostasis in dry multiparous dairy cows
    Acceleration of the Fe(III)EDTA(-) reduction rate in BioDeNO(x) reactors by dosing electron mediating compounds
    Maas, P.M.F. van der; Brink, P. van den; Klapwijk, A. ; Lens, P.N.L. - \ 2009
    Chemosphere 75 (2009)2. - ISSN 0045-6535 - p. 243 - 249.
    methanogenic bacteria - hydrogen-sulfide - reducing bacteria - nitrogen-oxides - chelated iron - nitric-oxide - fatty-acids - flue-gas - edta - absorption
    BioDeNO(x), a novel technique to remove NOx from industrial flue gases, is based on absorption of gaseous nitric oxide into an aqueous Fe(II)EDTA(2-) solution, followed by the biological reduction of Fe(II)EDTA(2-) complexed NO to N-2. Besides NO reduction, high rate biological Fe(III)EDTA(-) reduction is a crucial factor for a succesful application of the BioDeNO(x) technology, as it determines the Fe(II)EDTA(2-) concentration in the scrubber liquor and thus the efficiency of NO removal from the gas phase. This paper investigates the mechanism and kinetics of biological Fe(III)EDTA(-) reduction by unadapted anaerobic methanogenic sludge and BioDeNO(x) reactor mixed liquor. The influence of different electron donors, electron mediating compounds and CaSO3 on the Fe(III)EDTA(-) reduction rate was determined in batch experiments (21 mM Fe(III)EDTA(-), 55 degrees C, pH 7.2 +/- 0.2). The Fe(III)EDTA(-) reduction rate depended on the type of electron donor, the highest rate (13.9 mM h(-1)) was observed with glucose, followed by ethanol, acetate and hydrogen. Fe(III)EDTA(-) reduction occurred at a relatively slow (4.1 mM h(-1)) rate with methanol as the electron donor. Small amounts (0.5 mM) of sulfide, cysteine or elemental sulfur accelerated the Fe(III)EDTA(-) reduction. The amount of iron reduced significantly exceeded the amount that can be formed by the chemical reaction of sulfide with Fe(III)EDTA(-), suggesting that the Fe(III)EDTA(-) reduction was accelerated via an auto-catalytic process with an unidentified electron mediating compound, presumably polysulfides. formed out of the sulfur additives, Using ethanol as electron donor, the specific Fe(III)EDTA(-) reduction rate was linearly related to the amount of sulfide supplied. CaSO3 (0.5-100 mM) inhibited Fe(III)EDTA(-) reduction, probably because SO32- scavenged the electron mediating compound. 3
    Deriving inherent optical properties and associated inversion-uncertainties in the Dutch Lakes
    Salama, M.S. ; Dekker, A.G. ; Su, Z. ; Mannaerts, C.M.M. ; Verhoef, W. - \ 2009
    Hydrology and Earth System Sciences 13 (2009)7. - ISSN 1027-5606 - p. 1113 - 1121.
    resolution imaging spectrometer - dissolved organic-matter - zone color scanner - ocean color - chlorophyll-a - atmospheric correction - water-quality - coastal waters - model - absorption
    Remote sensing of water quality in inland waters requires reliable retrieval algorithms, accurate atmospheric correction and consistent method for uncertainty estimation. In this paper, the GSM semi-analytical inversion model is modified for inland waters to derive inherent optical properties (IOPs) and their spectral dependencies from air and space borne data. The modified model was validated using two data sets from the Veluwe and the Vecht Dutch lakes. For the Veluwe lakes, the model was able to derive a linear relationship between measured concentrations and estimated IOPs with R2 values above 0.7 for chlorophyll-a (Chl-a) and up to 0.9 for suspended particulate matters (SPM). In the Vecht lakes, the modified model derived accurate values of IOPs. The R2 values were 0.89 for Chl-a and up to 0.95 for SPM. The RMSE values were 0.93 mg m-3 and 0.56 g m-3 for Chl-a and SPM respectively. Finally, the IOPs of the Veluwe lakes are derived from multi-spectral, ocean color and hyperspectral airborne data. Inversion-uncertainties of the derived IOPs were also estimated using a standard nonlinear regression technique. The study shows that inversion-uncertainties of remote sensing derived IOPs are proportional to water turbidity
    Overweight children have higher circulating hepcidin concentrations and lower iron status but have dietary iron intakes and bioavailability comparable with normal weight children
    Aeberli, I. ; Hurrell, R.F. ; Zimmermann, M.B. - \ 2009
    International Journal of Obesity 33 (2009). - ISSN 0307-0565 - p. 1111 - 1117.
    for-disease-control - swiss children - united-states - nonheme-iron - subclinical inflammation - obese children - deficiency - absorption - women - adolescents
    Background: Obesity increases the risk for iron deficiency, but the underlying mechanism is unclear. It is possible that overweight individuals may have lower dietary iron intake and/or bioavailability. Alternatively, obesity-related inflammation may increase hepcidin concentrations and reduce iron availability. Circulating hepcidin levels have not been compared in normal weight vs overweight individuals. Objective: The objective of this study was to compare iron status, dietary iron intake and bioavailability, as well as circulating levels of hepcidin, leptin and interleukin-6 (IL-6), in overweight vs normal weight children. Design: In 6–14-year-old normal and overweight children (n=121), we measured dietary iron intake, estimated iron bioavailability and determined body mass index s.d. scores (BMI-SDS). In all children (n=121), we measured fasting serum ferritin, soluble transferrin receptor (sTfR), C-reactive protein (CRP) and leptin; in a subsample, we measured IL-6 (n=68) and serum hepcidin (n=30). Results: There were no significant differences in dietary iron intake or bioavailability comparing normal and overweight children. The prevalence of iron-deficient erythropoiesis (an increased sTfR concentration) was significantly higher in the overweight than in the normal weight children (20 vs 6%, P=0.022, with sTfR concentrations of 4.40±0.77 and 3.94±0.88¿mg¿l-1, respectively, P=0.010). Serum hepcidin levels were significantly higher in the overweight children (P=0.001). BMI-SDS significantly correlated with sTfR (P=0.009), serum hepcidin (P=0.005) and the three measures of subclinical inflammation, namely CRP (P
    Optimization of a phytase-containing micronutrient powder with low amounts of highly bioavailable iron for in-home fortification of complementary foods
    Troesch, B. ; Egli, I. ; Zeder, C. ; Hurrell, R.F. ; Pee, S. de; Zimmermann, M.B. - \ 2009
    American Journal of Clinical Nutrition 89 (2009)2. - ISSN 0002-9165 - p. 539 - 544.
    ascorbic-acid - phytic acid - nonheme-iron - infant formulas - fe(iii)-edta complex - breakfast meal - absorption - children - calcium - humans
    Background: In-home fortification of complementary foods with micronutrient powders containing low amounts of iron may be potentially safer than powders containing high amounts of iron. However, low iron doses have little nutritional effect, unless iron absorption is high. Objective: The objective was to maximize iron absorption from a low-iron micronutrient powder for in-home fortification by testing combinations of iron as NaFeEDTA, ascorbic acid, and a microbial phytase active at gut pH. In addition, a recently proposed enhancer of iron absorption, L--glycerophosphocholine (GPC), was tested. Design: In 6 separate iron-absorption studies using a crossover design, women (n = 101) consumed whole-maize porridge fortified with 3 mg stable isotope–labeled FeSO4 or NaFeEDTA with different combinations of enhancers added to the meals at the time of consumption. Incorporation of iron isotopes into erythrocytes 14 d later was measured. Results: The addition of phytase when iron was present as either NaFeEDTA or FeSO4, with or without ascorbic acid, significantly increased iron absorption. The combined addition of phytase, ascorbic acid, and NaFeEDTA resulted in an absorption of 7.4%, compared with an absorption of 1.5% from FeSO4 without enhancers in the same meal (P <0.001). The addition of ascorbic acid did not significantly increase iron absorption from NaFeEDTA, and the addition of calcium did not significantly inhibit iron absorption from NaFeEDTA in the presence of ascorbic acid. The addition of L--glycerophosphocholine did not significantly increase iron absorption. Conclusion: Optimization of the micronutrient powder increased iron absorption from a highly inhibitory meal 5-fold. This approach may allow for effective, untargeted in-home fortification of complementary foods with low amounts of highly bioavailable iron
    Plasma hepcidin is a modest predictor of dietary iron bioavailability in humans, whereas oral iron loading, measured by stable-isotope appearance curves, increases plasma hepcidin
    Zimmermann, M.B. ; Troesch, B. ; Biebinger, R. ; Egli, I. ; Zeder, C. ; Hurrell, R.F. - \ 2009
    American Journal of Clinical Nutrition 90 (2009)5. - ISSN 0002-9165 - p. 1280 - 1287.
    intestinal epithelial-cells - mass-spectrometry - serum hepcidin - absorption - ferroportin - deficiency - metabolism - women - mice - food
    Background: Plasma hepcidin appears to be a major regulator of iron absorption and homeostasis, but there are few data in humans. Objectives: With the use of iron stable isotopes, we aimed to determine whether circulating hepcidin predicts dietary iron bioavailability, to quantify the amount of absorbed iron after oral iron loading, and to measure the plasma hepcidin response. Design: In the first study, young women (n = 98) with an iron status varying from iron deficiency anemia to iron sufficiency (women with serum ferritin concentrations 25–40 µg/L were not included) were given stable isotope–labeled test meals (n = 196) containing ferrous sulfate, ferrous fumarate, or ferric pyrophosphate, after which plasma hepcidin and iron bioavailability were measured. In the second study, iron-sufficient men (n = 4) were given 3.8- and 60-mg oral doses of labeled ferrous sulfate. The stable isotope appearance curve was determined, and the plasma hepcidin response was measured over 6 h. Results: In study 1, plasma hepcidin and plasma ferritin were strongly correlated (r = 0.79, P <0.001). Plasma hepcidin significantly, but modestly, predicted iron bioavailability from ferrous sulfate and ferrous fumarate (r = –0.51 and –0.46, respectively; P <0.0001) but not from ferric pyrophosphate (r = –0.30, P = 0.056, respectively). In study 2, the 3.8-mg dose increased mean circulating absorbed iron to a peak of 0.42 µmol/L at 60 min but did not increase plasma hepcidin, The 60-mg dose increased mean circulating absorbed iron to a peak of 5.9 µmol/L at 120 min and produced an 30% increase in mean plasma hepcidin at 6 h (P <0.01). Conclusions: Plasma hepcidin is only a modest predictor of dietary iron bioavailability in humans. Oral iron loading, measured by stable-isotope appearance curves, increases circulating hepcidin
    Osmose houdt cellen op spanning : de drijvende kracht achter openen en sluiten van huidmondjes
    Heuvelink, E. ; Kierkels, T. - \ 2009
    Onder Glas 6 (2009)11. - p. 24 - 25.
    tuinbouwbedrijven - kassen - teelt onder bescherming - planten - osmose - absorberend vermogen - waterbalans - opname (uptake) - beweging van huidmondjes - sluitcellen - absorptie - glastuinbouw - market gardens - greenhouses - protected cultivation - plants - osmosis - absorptivity - water balance - uptake - stomatal movement - guard cells - absorption - greenhouse horticulture
    Osmose houdt cellen op spanning. Het is ook de druivende kracht achter openen en sluiten van huidmondjes. Bij de opname van water door de wortels, is osmose juist een tegenwerkende kracht, vooral bij een hogere EC. Aandacht voor watervoorziening, EC kalium- en calciumvoorziening is nodig om de zaken goed te laten verlopen
    Development and evaluation of a dynamic model of calcium and phosphorus flows in layers
    Kebreab, E. ; France, J. ; Kwakkel, R.P. ; Leeson, S. ; Darmani Kuhi, H. ; Dijkstra, J. - \ 2009
    Poultry Science 88 (2009)3. - ISSN 0032-5791 - p. 680 - 689.
    dietary calcium - gastrointestinal-tract - ovulatory cycle - laying fowl - hens - absorption - requirement - minerals - quality - protein
    Phosphorus is an essential nutrient involved in most metabolic processes. Most of the interest in Ca metabolism relates to eggshell formation. Although the eggshell is composed of Ca carbonate, metabolism of both Ca and P is closely related such that a deficiency in one can interfere with proper utilization of the other. To understand Ca and P metabolism properly, modeling can be of paramount importance. A new dynamic and mechanistic model of P and Ca metabolism in layers has been developed to simulate diurnal changes in Ca and P and the hourly requirement of the layer for those minerals. The model consists of 8 state variables representing Ca and P pools in the crop, stomachs, plasma, and bone. The flow equations are described by Michaelis-Menten or mass action forms. An experiment that measured Ca and P uptake in layers fed different Ca concentrations during shell-forming days was used for model evaluation. The experiment showed that Ca retained in body and egg decreased from 62.5 to 50.5% of Ca intake when the Ca in diet was increased from 25 to 45 mg/g of feed. The model simulations were in agreement with the trend. Predictions of Ca retention in bone and egg were 63.2, 56.1, and 55.3% for low, medium, and high dietary Ca concentrations. The experimental results showed that P retention in body and egg increased significantly from 11.5% of absorbable P intake at the lowest Ca inclusion concentration to 24.1% at the highest. The model also predicted an increase in P retention in bone and egg from 8.4 to 25.4% of absorbable P intake at the lowest and highest concentration of Ca inclusion, respectively. The advantage of the model is that absorption and utilization can be monitored on an hourly basis and that adjustments can be made accordingly. The model successfully showed how the availability of one mineral affects the utilization of the other and is a useful tool to evaluate feeding strategies aimed at reducing P excretion to the environment in poultry manure
    Procyanidin Dimers A1, A2, and B2 Are Absorbed without Conjugation or Methylation from the Small Intestine of Rats1–3
    Appeldoorn, M.M. ; Vincken, J.P. ; Gruppen, H. ; Hollman, P.C.H. - \ 2009
    The Journal of Nutrition 139 (2009)8. - ISSN 0022-3166 - p. 1469 - 1473.
    flavanol-rich cocoa - (-)-epicatechin metabolites - bioavailability - polyphenols - humans - plasma - absorption - epicatechin-(4-beta-8)-epicatechin - identification - consumption
    Intervention studies with procyanidin (PC)-rich extracts and products such as cocoa and wine suggest protective effects of PC against cardiovascular diseases. However, there is no consensus on the absorption and metabolism of PC dimers. Interestingly, nothing is known about the absorption of A-type PC. In this study, the absorption and metabolism of purified PC dimers A1 [epicatechin-(2-O-7, 4–8)-catechin], A2 [epicatechin-(2-O-7, 4–8)-epicatechin], and B2 [epicatechin-(4–8)-epicatechin], A-type trimers, a mixture of A1, B2, and a tetrameric A-type, and monomeric epicatechin were compared by in situ perfusion of the small intestine of rats for 0–30 min. The rats had their bile duct, portal vein, and small intestine cannulated. Unmodified and methylated metabolites were distinguished from their conjugates by differential ß-glucuronidase treatment. A1 and A2 dimers were absorbed from the small intestine of rats and they were better absorbed than dimer B2. Absorption of the A-type dimers was only 5–10% of that of monomeric epicatechin. Dimers were not conjugated or methylated in contrast to epicatechin, which was partly methylated and 100% conjugated. A-type trimers were not absorbed. Furthermore, the presence of tetrameric PC enhanced the absorption of B2 but not that of A1. Epicatechin, methylated epicatechin, and their conjugates were not found as metabolites of the PC tested. In conclusion, dimers A1, A2, and B2 are slightly absorbed but are not conjugated or methylated, thus conserving their biological activity after absorption. Because PC contents of foods are relatively high, dimers may contribute to systemic effects of PC.
    Dietary intake of zinc in the population of Jiangsu Province, China.
    Yu, Q. ; Boonstra, A. ; Shi, Z. ; Pan, X. ; Yuan, B. ; Dai, Yue ; Zhao, J. ; Zimmermann, M.B. ; Kok, F.J. ; Zhou, M. - \ 2009
    Asia Pacific Journal of Clinical Nutrition 18 (2009)2. - ISSN 0964-7058 - p. 193 - 199.
    preschool-children - iron intake - adults - association - people - absorption - calcium - phytate - anemia
    Objectives: To evaluate dietary zinc and other divalent minerals intake among the population of Jiangsu Province. Methods: 3,867 subjects aged 4-89 years were representatively sampled in two urban and six rural areas of Jiangsu Province. Dietary intake was assessed using 24-hour recalls on three consecutive days. Insufficient zinc intake was calculated based on the Chinese Dietary Reference Intakes. Results: Overall, the percentage of subjects with insufficient intake of zinc was 22.9%, with a declining trend with age. Except for the group >=50 years, mean zinc intake of all other groups were below the age- and sex- specific Recommended Nutrition Intakes (RNI). Approximately 2/3rds of the subjects =50 years (OR: 0.76, 95% CI: 0.66-0.8; OR:0.55, 95%CI: 0.47-0.64). Mean intake of iron, copper, magnesium and selenium met the Chinese DRIs respectively, except for selenium in females. The prevalence of insufficient intake of copper, magnesium and selenium was 37.2%, 22.8% and 29.3%, respectively, while the overall prevalence of insufficient iron intake was only 3.4%. Conclusion: Dietary zinc intake of the Jiangsu Province population does not generally meet the Chinese RNI. Children and adolescents in particular have a higher risk of insufficient zinc intake
    Identification of strong aggregating regions in soy glycinin upon enzymatic hydrolysis
    Kuipers, B.J.H. ; Gruppen, H. - \ 2008
    Journal of Agricultural and Food Chemistry 56 (2008)10. - ISSN 0021-8561 - p. 3818 - 3827.
    whey-protein isolate - mass-spectrometry - amino-acids - gelation - peptide - coagulation - mechanism - purification - absorption - bromelain
    Upon hydrolysis with chymotrypsin, soy glycinin has a strong tendency to aggregate. The regions of glycinin from which the aggregating peptides originate were identified by accumulative-quantitative peptide mapping. To this end, the aggregating peptides were further hydrolyzed with trypsin to obtain peptides of which the sequence can be identified using RP-HPLC-MS/MS. This resulted in a hydrolysate in which 90% of the proteinaceous material was dissolved. The soluble fraction was analyzed using the method of accumulative-quantitative peptide mapping: fractionation using ion exchange chromatography, followed by identification of peptides by RP-HPLC-MS/MS, quantification based on the absorbance at 214 nm, and finally peptide mapping. For the peptide mapping the proportions in which each of the five glycinin subunits are present, as determined by Edman degradation, were taken into account. The results showed that mainly the basic polypeptide and a part of the acidic polypeptide, close to the location of the disulfide bridge between the basic and acidic polypeptides, are present in the aggregating peptide fraction. On the basis of the results obtained, an aggregation mechanism was proposed. The hydrophilic acidic polypeptides shield the hydrophobic basic polypeptides, and the former are preferentially degraded upon hydrolysis. This results in a net increase in hydrophobicity of the remaining material, which mainly consists of the basic polypeptide fragments. This increase in hydrophobicity is proposed to be the driving force in the aggregation of chymotrypsin-derived peptides of glycinin.
    Association between consumption of black tea and iron status in adult Africans in the North West Province: The THUSA study
    Hogenkamp, P.S. ; Jerling, J.C. ; Hoekstra, T. ; Boonstra, A. ; MacIntyre, U.E. - \ 2008
    The British journal of nutrition 100 (2008)2. - ISSN 0007-1145 - p. 430 - 437.
    antioxidant activity - hiv-infection - absorption - milk - women - population - bioavailability - beverages - rooibos - health
    The association between black tea consumption and iron status was investigated in a sample of African adults participating in the cross-sectional THUSA (Transition and Health during Urbanization of South Africans) study in the North West Province, South Africa. Data were analysed from 1605 apparently healthy adults aged 15-65 years by demographic and FFQ, anthropometric measurements and biochemical analyses. The main outcome measures were Hb and serum ferritin concentrations. No associations were seen between black tea consumption and concentrations of serum ferritin (men P=0.059; women P=0.49) or Hb (men P=0.33; women P=0.49). Logistic regression showed that tea consumption did not significantly increase risk for iron deficiency (men: OR 1.36; 95 % CI 0.99, 1.87; women: OR 0.98; 95 % CI 0.84, 1.13) nor for iron deficiency anaemia (men: OR 1.28: 95 % Cl 0.84, 1.96; women: OR 0.93; 95 % Cl 0.78, 1.11). Prevalence of iron deficiency and iron deficiency anaemia was especially high in women: 21.6 and 14.6 %, respectively. However, the likelihood of iron deficiency and iron deficiency anaemia was not significantly explained by tea consumption in sub-populations which were assumed to be at risk for iron deficiency. Regression of serum ferritin levels on tea consumption in women : 40 years, adults with a daily iron intake
    Fatty Acid Digestion and Deposition in Broiler Chickens Fed Diets Containing Either Native or Randomized Palm Oil
    Smink, W. ; Gerrits, W.J.J. ; Hovenier, R. ; Geelen, M.J.H. ; Lobee, H.W.J. ; Verstegen, M.W.A. ; Beynen, A.C. - \ 2008
    Poultry Science 87 (2008). - ISSN 0032-5791 - p. 506 - 513.
    metabolizable energy - digestibility - lard - triacylglycerols - absorption - saturation - tissues - lipids
    The hypothesis tested was that randomization of palm oil would increase its digestibility, especially that of its palmitic acid (C16:0) component, with subsequent changes in the fatty acid composition in body tissues. Broiler chickens were fed diets containing either native or randomized palm oil. Diets with either native or a 50/50 mix of native and hydrogenated sunflower oil were also fed. Randomization of palm oil raised the fraction of C16:0 at the sn-2 position of the glycerol molecule from 14 to 32%. Hydrogenation of sunflower oil reduced fat and total saturated fatty acid digestibility, whereas no change in digestibility of total unsaturated fatty acids was found. Randomization of palm oil raised the group mean apparent digestibility of C16:0 by 2.6 and 5.8% units during the starter and grower-finisher phase, respectively. On the basis of the observed digestibilities in the grower-finisher period, it was calculated that the digestibility for C16:0 at the sn-2 and sn-1,3 position was 90 and 51%, respectively. The feeding of randomized instead of native palm oil significantly raised the palmitic acid content of breast meat and abdominal fat and lowered the ratio of unsaturated to saturated fatty acids. It is concluded that randomized palm oil may be used as vegetable oil in broiler nutrition with positive effect on saturated fatty acid digestibility when compared with native palm oil and positive effect on firmness of meat when compared with vegetable oils rich in unsaturated fatty acids.
    The Effect of Silage and Concentrate Type on Intake Behavior, Rumen Function, and Milk Production in Dairy Cows in Early and Late Lactation
    Abrahamse, P.A. ; Vlaeminck, B. ; Tamminga, S. ; Dijkstra, J. - \ 2008
    Journal of Dairy Science 91 (2008)12. - ISSN 0022-0302 - p. 4778 - 4792.
    feeding-behavior - perennial ryegrass - transition period - corn-silage - patterns - drinking - cattle - diets - performance - absorption
    The objective of this experiment was to evaluate the effect of feeding total mixed rations (TMR) that differ in structural and nonstructural carbohydrates to dairy cows in early and late lactation on short-term feed intake, dry matter intake (DMI), rumen fermentation variables, and milk yield. A 5 x 5 Latin square experiment with 15 dairy cows was repeated during early and late lactation. The 5 treatments were a TMR with ( all on dry matter basis) 55% roughage ( a 50: 50 mixture of corn silage and grass silage) and 45% concentrate ( a 50: 50 mixture of concentrate rich in structural carbohydrates and concentrate rich in nonstructural carbohydrates; treatment CON), a TMR with the concentrate mixture and 55% grass silage (RGS) or 55% corn silage (RCS), and a TMR with the roughage mixture and 45% of the concentrate rich in structural carbohydrates (CSC) or the concentrate rich in nonstructural carbohydrates (CNS). Meal criteria, determined using the Gaussian-Gaussian-Weibull method per animal per treatment, showed an interaction between lactation stage and treatment. Feed intake behavior variables were therefore calculated with meal criteria per treatment-lactation stage combination. Differences in feed intake behavior were more pronounced between treatments differing in roughage composition than between treatments differing in concentrate composition, probably related to larger differences in chemical composition and particle size between corn silage and grass silage than between the 2 concentrates. The number of meals was similar between treatments, but eating time was greater in RGS ( 227 min/d) and lesser in RCS ( 177 min/d) than the other treatments. Intake rate increased when the amount of grass silage decreased, whereas meal duration decreased simultaneously. These effects were in line with a decreased DMI of the RGS diet vs. the other treatments, probably related to the high neutral detergent fiber (NDF) content. However, this effect was not found in CSC, although NDF content of the TMR, fractional clearance rate of NDF, and fractional degradation rate of NDF was similar between CSC and RGS. Rumen fluid pH was lesser, and molar proportions of acetic acid and of propionic acid were lesser and greater, respectively, in RCS compared with all other diets. Milk production did not differ between treatments. There was no effect of type of concentrate on milk composition, but diet RCS resulted in a lesser milk fat content and greater milk protein content than diet RGS. Lactation stage did affect short-term feed intake behavior and DMI, although different grass silages were fed during early and late lactation. The results indicate that short-term feed intake behavior is related to DMI and therefore may be a helpful tool in optimizing DMI and milk production in high-production dairy cows.
    Brief communication: Soybean meal-induced uptake block in Atlantic salmon Salmo salar distal enterocytes
    Urán, P. ; Aydin, R. ; Schrama, J.W. ; Verreth, J.A.J. ; Rombout, J.H.W.M. - \ 2008
    Journal of Fish Biology 73 (2008)10. - ISSN 0022-1112 - p. 2571 - 2579.
    ctenopharyngodon-idella val - trout oncorhynchus-mykiss - induced enteritis - rainbow-trout - intestinal epithelium - l. - transport - carp - gut - absorption
    Soybean meal-induced enteritis was characterized by the disappearance of the supranuclear vacuoles (SNV) in the enterocytes of the distal intestine of Atlantic salmon Salmo salar. The loss of SNV was correlated with an endocytosis uptake block as shown with ferritin as a marker molecule.
    Iron metabolism in heterozygotes for hemoglobin E (HbE), alpha-thalassemia1, or beta-thalassemia and in compound heterozygotes for HbE/ beta-thalassemia
    Zimmermann, M.B. ; Fucharoen, S. ; Winichagoon, P. ; Sirankapracha, P. ; Zeder, C. ; Gowachirapant, S. ; Judprasong, K. ; Tanno, T. ; Miller, J.L. ; Hurrell, R.F. - \ 2008
    American Journal of Clinical Nutrition 88 (2008)4. - ISSN 0002-9165 - p. 1026 - 1031.
    cell-cycle distribution - serum ferritin levels - idiopathic hemochromatosis - erythropoietic cells - loading anemias - food iron - absorption - overload - trait - hepcidin
    BACKGROUND: Despite large populations carrying traits for thalassemia in countries implementing universal iron fortification, there are few data on the absorption and utilization of iron in these persons. OBJECTIVE: We aimed to determine whether iron absorption or utilization (or both) in women heterozygous for beta-thalassemia, alpha-thalassemia 1, or hemoglobin E (HbE) differed from that in control subjects and compound HbE/beta-thalassemia heterozygotes. DESIGN: In Thai women (n = 103), red blood cell indexes, iron status, non-transferrin-bound iron, and growth differentiation factor 15 were measured, and body iron was calculated. Fractional iron absorption was measured from meals fortified with isotopically labeled ((57)Fe) Fe sulfate, and iron utilization was measured by the infusion of ((58)Fe) Fe citrate. RESULTS: Iron utilization was approximately 15% lower in alpha-thalassemia 1 or beta-thalassemia heterozygotes than in controls. When corrected for differences in serum ferritin, absorption was significantly higher in the alpha- and beta-thalassemia groups, but not the HbE heterozygotes, than in controls. HbE/beta-thalassemia compound heterozygotes had lower iron utilization and higher iron absorption and body iron than did controls. Nontransferrin-bound iron and growth differentiation factor 15 were higher in the compound heterozygotes, but not in the other groups, than in the controls. CONCLUSIONS: In alpha-thalassemia 1 and beta-thalassemia heterozygotes with ineffective erythropoesis, dietary iron absorption is not adequately down-regulated, despite a modest increase in body iron stores. In populations with a high prevalence of these traits, a program of iron fortification could include monitoring for possible iron excess and for iron deficiency.
    A cholesterol-free, high-fat diet suppresses gene expression of cholesterol transporters in murine small intestine
    Bosch, H.M. van den; Wit, N.J.W. de; Hooiveld, G.J.E.J. ; Vermeulen, H. ; Veen, J.N. van der; Houten, S.M. ; Kuipers, F. ; Müller, M.R. ; Meer, R. van der - \ 2008
    American Journal of Physiology. Gastrointestinal and Liver Physiology 294 (2008)5. - ISSN 0193-1857 - p. G1171 - G1180.
    liver-x-receptor - cellular cholesterol - caco-2 cells - lxr-alpha - absorption - mice - secretion - metabolism - activation - excretion
    Transporters present in the epithelium of the small intestine determine the efficiency by which dietary and biliary cholesterol are taken up into the body and thus control whole-body cholesterol balance. Niemann-Pick C1 Like Protein 1 (Npc1l1) transports cholesterol into the enterocyte, whereas ATP-binding cassette transporters Abca1 and Abcg5/Abcg8 are presumed to be involved in cholesterol efflux from the enterocyte toward plasma HDL and back into the intestinal lumen, respectively. Abca1, Abcg5, and Abcg8 are well-established liver X receptor (LXR) target genes. We examined the effects of a high-fat diet on expression and function of cholesterol transporters in the small intestine in mice. Npc1l1, Abca1, Abcg5, and Abcg8 were all downregulated after 2, 4, and 8 wk on a cholesterol-free, high-fat diet. The high-fat diet did not affect biliary cholesterol secretion but diminished fractional cholesterol absorption from 61 to 42% (P <0.05). In an acute experiment in which triacylglycerols of unsaturated fatty acids were given by gavage, we found that this downregulation occurs within a 6-h time frame. Studies in LXR-null mice, confirmed by in vitro data, showed that fatty acid-induced downregulation of cholesterol transporters is LXR independent and associated with a posttranslational increase in 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity that reflects induction of cholesterol biosynthesis as well as with a doubling of neutral fecal sterol loss. This study highlights the induction of adaptive changes in small intestinal cholesterol metabolism during exposure to dietary fat.
    Activation of EpRE-mediated gene transcription by quercetin glucuronides depends on their deconjugation
    Lee, Y.Y. ; Stolaki, M. ; Berkel, W.J.H. van; Aarts, J.M.M.J.G. ; Rietjens, I.M.C.M. - \ 2008
    Food and Chemical Toxicology 46 (2008)6. - ISSN 0278-6915 - p. 2128 - 2134.
    dietary polyphenols - in-vitro - metabolic-fate - flavonoids - expression - absorption - glycosides - humans - cells - model
    Quercetin is a flavonoid reported to have health-promoting properties. Due to its extensive metabolism to glucuronides in vivo, questions were raised if studies conducted with quercetin aglycone, stating its health-promoting activity, are of actual relevance. Here we show that glucuronides of quercetin, and its methylated forms isorhamnetin and tamarixetin, can induce EpRE-mediated gene expression up to 5-fold. Furthermore, evidence is presented that EpRE-mediated gene induction by these glucuronides involves their deglucuronidation. This indicates that although quercetin-derived glucuronides are the major metabolites present in the systemic circulation, deglucuronidated derivatives are the active compounds responsible for their beneficial EpRE-mediated gene expression effects.
    Citrulline and intestinal fatty acid-binding protein: Longitudinal markers of postweaning small intestinal function in pigs?
    Berkeveld, M. ; Langendijk, P. ; Verheijden, J.H.M. ; Taverne, M.A.M. ; Nes, A. van; Haard, P. van; Koets, A.P. - \ 2008
    Journal of Animal Science 86 (2008)12. - ISSN 0021-8812 - p. 3440 - 3449.
    enhanced expression - plasma citrulline - enterocyte mass - crypt depth - weaned pigs - feed-intake - piglets - glutamine - absorption - morphology
    The objective of the current study was to investigate whether plasma citrulline or intestinal fatty acid-binding protein (I-FABP) concentrations might be used as longitudinal markers for small intestinal function in piglets after weaning. Plasma citrulline and I-FABP concentrations were measured longitudinally in weaned and unweaned piglets, and related to intestinal absorption values (i.e., plasma mannitol and 3-xylose concentrations in a sugar absorption test). Within each litter (n = 10), 2 piglets with a close-to-litter-average BW were selected. At 20.8 ± 0.4 d of age, the selected piglets per litter were either weaned conventionally (CW) or remained with the sow (UNW). One day before, and 0.5, 2, 4, and 7 d after weaning of the CW piglets, the selected piglets of both groups were subjected to a sugar absorption test. After a 2-h fast, piglets were administered an oral dose of 2 mL/kg of sugar solution, containing 50 mg/kg of mannitol and 100 mg/kg of 3-xylose. One hour after administration, a blood sample was collected from a jugular vein for determination of plasma I-FABP, citrulline, mannitol, and 3-xylose concentrations. Plasma I-FABP concentration showed great variation within treatments, and no difference was observed in plasma I-FABP concentrations between the CW and UNW treatments (P = 0.63). The absorption of 3-xylose was not different between treatments (P = 0.83). Mannitol absorption, however, was less in the weaned CW piglets compared with the UNW piglets (P = 0.003), with the nadir on d 4 postweaning. Weaning also reduced plasma citrulline concentrations in the CW treatment compared with the UNW treatment (P <0.001). On d 4 and 7 postweaning, plasma citrulline concentrations of CW piglets were less (P <0.001 and P = 0.0013) than preweaning values. Furthermore, in the CW treatment, plasma citrulline concentrations correlated with plasma mannitol concentrations at d 4 postweaning (r = 0.89, P = 0.008) and overall (r = 0.76, P = 0.001). Based on these results, plasma citrulline concentration seems to be a possible marker for monitoring intestinal function in pigs after weaning.
    Energy efficient multistage zeolite drying for heat sensitive products
    Djaeni, M. - \ 2008
    Wageningen University. Promotor(en): Gerrit van Straten; Johan Sanders, co-promotor(en): Ton van Boxtel; Paul Bartels. - [S.l.] : S.n. - ISBN 9789085852094 - 162
    drogers - drogen - droogmethoden - absorptie - adsorptie - adsorberende middelen - energiegebruik - ontvochtiging - drogende lucht - energiebesparing - computationele vloeistofdynamica - driers - drying - drying methods - absorption - adsorption - adsorbents - energy consumption - dehumidification - drying air - energy saving - computational fluid dynamics
    Although drying takes a significant part of the total energy usage in industry, currently available drying technology is often not efficient in terms of energy consumption. Generally, the energy efficiency for drying processes ranges between 20-60% depending on the dryer type and product to be dried. This research focuses on the development of single and multistage zeolite drying combined with heat recovery unit to enhance the energy efficiency. The evaluation using steady state and two dimensional model showed that for single stage system the energy efficiency can reach 70-75% and it increases corresponding to the stage number. For 2-3 stages, the energy efficiency 80-90% can be achieved. The experimental work using single stage zeolite dryer also showed that the energy efficiency is close to conceptual approach. Based on the impressive results, a number of potential options have been formulated to construct the zeolite dryer in continuous operating systems for industrial application.
    Modelling the implications of feeding strategy on rumen fermentation and functioning of the rumen wall
    Bannink, A. ; France, J. ; Lopez, S. ; Gerrits, W.J.J. ; Kebreab, E. ; Tamminga, S. ; Dijkstra, J. - \ 2008
    Animal Feed Science and Technology 143 (2008)1-4. - ISSN 0377-8401 - p. 3 - 26.
    volatile fatty-acids - lactating dairy-cows - splanchnic metabolism - washed reticulorumen - nutrient digestion - mechanistic model - water kinetics - late-gestation - energy costs - absorption
    The present study gives a critique of the mechanisms involved with the formation of volatile fatty acid (VFA) formed in the lumen of the reticulo-rumen, the absorption of VFA across the reticulo-rumen wall, and the intra-epithelial metabolism of VFA by reticulo-rumen epithelium. In contrast to the empirical treatment of these aspects in previous rumen modelling studies, a mechanistic model was developed which represents each of these aspects separately. Because tissues of the reticulo-rumen may strongly adapt to changing nutritional conditions, this adaptive response was included in the model. The model enabled an evaluation of the implications of VFA yield on the development of the rumen wall, on the transport of VFA, on the extent of intra-epithelial metabolism of VFA, and on the consequences for the supply of VFA to the ruminant. The current modelling effort allowed the integration of existing knowledge on each of these aspects and the model reproduced some essential characteristics of experimental observations on VFA absorption and metabolism. Although further development is still needed, the model appears helpful to distinguish elements that require specific consideration when evaluating rates of net portal appearance of VFA, or when testing hypothesis on the interaction between formation, absorption and intra-epithelial metabolism of VFA under various experimental conditions
    Trees : relief for the city
    Hiemstra, J.A. ; Schoenmaker-van der Bijl, E. ; Tonneijck, A.E.G. ; Hoffman, M.H.A. - \ 2008
    Boskoop : Plant Publicity Holland - 33
    bomen - luchtkwaliteit - luchtverontreiniging - stedelijke gebieden - steden - stof - ozon - stikstofoxiden - windschermen - absorptie - nederland - fijn stof - trees - air quality - air pollution - urban areas - towns - dust - ozone - nitrogen oxides - windbreaks - absorption - netherlands - particulate matter
    This brochure describes the underlying principles that form a basis for better-informed choices with regards to the management of trees and shrubs in cities and the design of functional planting schemes.
    The supply of bioavailable iron and zinc may be affected by phytate in Beninese children
    Mitchikpe, C.E.S. ; Dossa, R.A.M. ; Ategbo, E.A.D. ; Raaij, J.M.A. van; Hulshof, P.J.M. ; Kok, F.J. - \ 2008
    Journal of Food Composition and Analysis 21 (2008)1. - ISSN 0889-1575 - p. 17 - 25.
    absorption - maize - foods - availability - fermentation - consumption - nutrition - district - calcium - soaking
    Food composition data are important for estimating energy and nutrient intakes. The objectives of this study were, first, to evaluate the proximate and inorganic composition of foods eaten in northern Benin and second, to estimate the potentially inhibiting effect of phytate on iron and zinc bioavailability. Chemical analyses were performed in 23 samples of most frequently consumed foodstuffs collected from retailers in local markets. Proximate composition was analysed by routine methods. Inorganic constituents and phytate were analysed using ICP-AES and HPLC. Protein contents were in agreement with those in FAO food composition database. Fat and fibre were in general higher whereas carbohydrate and energy were lower. Differences were mainly due to analytical or calculation methods. The most important sources of iron and zinc in children's diets were maize, sorghum and millet. In these cereals, iron and zinc ranged from 2.6 to 8.4 and 2.2 to 3.4 mg/100 g, respectively. Phytate ranged from 104 to 503 mg/100 g. Phytate/iron and phytate/zinc molar ratios ranged from 1 to 11 and 3 to 22, respectively. They suggest poor iron and zinc bioavailability. Reducing phytate and polyphenol contents in order to improve iron and zinc bioavailability from the most frequently consumed cereal food needs to be studied.
    Synthesis, characterization, and bioavailability in rats of ferric phosphate nanoparticles
    Rohner, F. ; Ernst, F.O. ; Arnold, M. ; Hilbe, M. ; Biebinger, R. ; Ehrensperger, F. ; Pratsinis, S.E. ; Langhans, W. ; Hurrell, R.F. ; Zimmermann, M.B. - \ 2007
    The Journal of Nutrition 137 (2007)3. - ISSN 0022-3166 - p. 614 - 619.
    flame spray-pyrolysis - particle-size - iron bioavailability - delivery-system - pyrophosphate - nanotechnology - fortification - absorption - toxicity - powders
    Particle size is a determinant of iron (Fe) absorption from poorly soluble Fe compounds. Decreasing the particle size of metallic Fe and ferric pyrophosphate added to foods increases Fe absorption. The aim of this study was to develop and characterize nanoparticles of FePO4 and determine their bioavailability and potential toxicity in rats. Amorphous FePO4 nanopowders with spherical structure were synthesized by flame spray pyrolysis (FSP). The nanopowders were characterized and compared with commercially available FePO4 and FeSO4, including measurements of specific surface area (SSA), structure by transmission electron microscopy, in vitro solubility at pH 1 and 2, and relative bioavailability value (RBV) to FeSO4 in rats using the hemoglobin repletion method. In the latter, the potential toxicity after Fe repletion was assessed by histological examination and measurement of thiobarbituric acid reactive substances (TBARS). The commercial FePO4 and the 2 FePO4 produced by FSP (mean particle sizes, 30.5 and 10.7 nm) had the following characteristics: SSA: 32.6, 68.6, 194.7 m2/g; in vitro solubility after 30 min at pH 1: 73, 79, and 85% of FeSO4; and RBV: 61, 70, and 96%, respectively. In the histological examinations and TBARS analysis, there were no indications of toxicity. In conclusion, nanoparticles of FePO4 have a solubility and RBV not significantly different from FeSO4. Reducing poorly soluble Fe compounds to nanoscale may increase their value for human nutrition.
    A comparison of physical properties, screening procedures and a human efficacy trial for predicting the bioavailability of commercial elemental iron powders used for food fortification
    Zimmermann, M.B. ; Lynch, S.R. ; Bothwell, T. - \ 2007
    International Journal for Vitamin and Nutrition Research 77 (2007)2. - ISSN 0300-9831 - p. 107 - 124.
    task-force report - carbonyl iron - double-blind - absorption - availability - invitro - cereals - flour - meals - model
    Elemental iron powders are widely used to fortify staple foods. This paper summarizes physical and chemical measurements that were conducted to assess the bioavailability of these iron powders relative to ferrous sulfate, along with validation of these assessments from a study with human subjects. Commercial elemental iron powders varied in bioavailability depending on the manufacturing process. Measurements of particle surface area and of solubility compared well with measurements conducted with animal absorption and with improvement of iron status in Thai women. The dissolution rate of the elemental iron powders in dilute acid, according to a standardized procedure, may be useful as an estimate of bioavailability. Carbonyl and electrolytic iron were found to have the best bioavailability of the iron powders, and reduced forms of iron were generally less bioavailable. This research will be useful in selecting iron products to fortify foods in areas of the world that need dietary iron fortification to fight a high incidence of iron deficiency and iron deficiency anemia.
    Effects of dietary water holding capacity and level of fermentable organic matter on digesta passage in various parts of the digestive tract in growing pigs
    Leeuwen, P. van; Jansman, A.J.M. - \ 2007
    Livestock Science 109 (2007)1-3. - ISSN 1871-1413 - p. 77 - 80.
    gastric-emptying rate - fiber - polysaccharides - absorption - starch - flow
    The effect diet composition on digesta passage over three sections of the gastro-intestinal tract (GIT) was studied in growing pigs. A control diet (C diet) and three diets differing in the contents of non-starch polysaccharides (NSP) and water holding capacity (WHC) were fed. Results showed a mean transit time (MTT) over the whole GIT over all diets of 75 h. NSP significantly (P <0.05) decreased MTT over the total GIT and through the large intestine. In contrast, NSP tended to increase the MTT of the stomach contents (P <0.10). The effects of WHC were limited to tendencies for a decrease of the MTT in the large intestine (P <0.10) and an increase of the MTT in the small intestine (P <0.10).
    The third RAdiation transfer Model Intercomparison (RAMI) exercise: Documenting progress in canopy reflectance models
    Widlowski, J.L. ; Taberner, M. ; Pinty, B. ; Bruniquel-Pinel, V. ; Disney, M.I. ; Fernandes, R. ; Gastellu-Etchegorry, J.P. ; Gobron, N. ; Kuusk, A. ; Lavergne, T. ; LeBlanc, S. ; Lewis, P.E. ; Martin, E. ; Mõttus, M. ; North, P.R.J. ; Qin, W. ; Robustelli, M. ; Rochdi, N. ; Ruiloba, R. ; Thompson, R. ; Verhoef, W. ; Verstraete, M.M. ; Xie, D. - \ 2007
    Journal of Geophysical Research: Atmospheres 112 (2007). - ISSN 2169-897X
    digital hemispherical photography - vegetation canopies - leaf orientation - solar-radiation - plant canopies - scattering - project - surface - validation - absorption
    [1] The Radiation Transfer Model Intercomparison ( RAMI) initiative benchmarks canopy reflectance models under well-controlled experimental conditions. Launched for the first time in 1999, this triennial community exercise encourages the systematic evaluation of canopy reflectance models on a voluntary basis. The first phase of RAMI focused on documenting the spread among radiative transfer (RT) simulations over a small set of primarily 1-D canopies. The second phase expanded the scope to include structurally complex 3-D plant architectures with and without background topography. Here sometimes significant discrepancies were noted which effectively prevented the definition of a reliable "surrogate truth,'' over heterogeneous vegetation canopies, against which other RT models could then be compared. The present paper documents the outcome of the third phase of RAMI, highlighting both the significant progress that has been made in terms of model agreement since RAMI-2 and the capability of/need for RT models to accurately reproduce local estimates of radiative quantities under conditions that are reminiscent of in situ measurements. Our assessment of the self-consistency and the relative and absolute performance of 3-D Monte Carlo models in RAMI-3 supports their usage in the generation of a "surrogate truth'' for all RAMI test cases. This development then leads ( 1) to the presentation of the "RAMI Online Model Checker'' (ROMC), an open-access web-based interface to evaluate RT models automatically, and ( 2) to a reassessment of the role, scope, and opportunities of the RAMI project in the future.
    Functional Region Identification in Proteins by Accumulative-Quantitative Peptide Mapping Using RP-HPLC-MS
    Kuipers, B.J.H. ; Bakx, E.J. ; Gruppen, H. - \ 2007
    Journal of Agricultural and Food Chemistry 55 (2007)23. - ISSN 0021-8561 - p. 9337 - 9344.
    mass-spectrometry - soy proteins - absorption - allergen - acids
    A new method was developed to identify regions in proteins from which peptides are derived with specific functional properties. This method is applicable for systems in which peptides of a hydrolyzed protein possess specific functional properties, but are too large to be sequenced directly and/or the peptide mixture is too complex to purify and characterize each peptide individually. In the present work, aggregating peptides obtained by proteolytic hydrolysis of soy glycinin were used as a case study. The aggregating peptides are isolated and subsequently further degraded with trypsin to result in peptides with a mass
    The Potential of Increased Meat Intake to Improve Iron Nutrition in Rural Kenyan Schoolchildren
    Grillenberger, M. ; Murphy, S.P. ; Neumann, C.G. ; Bwibo, N.O. ; Verhoef, H. ; Hautvast, J.G.A.J. - \ 2007
    International Journal for Vitamin and Nutrition Research 77 (2007)3. - ISSN 0300-9831 - p. 193 - 198.
    animal source foods - ascorbic-acid - dietary iron - developing-countries - malawian children - school-children - bioavailability - intervention - consumption - absorption
    Schoolchildren in developing countries often have inadequate intakes of iron, due primarily to poor I bioavailability. Increasing meat in the diet could improve both the amount of iron consumed and its availability. The effect of increases in intakes of meat and ascorbic acid on absorbed iron was investigated by theoretically modifying the habitual diet of rural Kenyan schoolchildren. The projected changes in the amount of absorbed iron and prevalence of inadequate iron intakes were calculated for 78 children (6-9 years of age). The prevalence of inadequate iron intakes decreased from 77% to 54% through the theoretical addition of 50 g beef prevalence or 100 mg ascorbic acid and to 23% through the addition of both to dinner each day. To reduce the of inadequate iron intake to 5%, the addition of 100 g meat plus 150 mg ascorbic acid would be necessary. The combined addition of meat and ascorbic acid to a meal has the potential to reduce the,projected prevalence of inadequate iron intakes among these schoolchildren.
    Modelling volatile fatty acid dynamics and rumen function in lactating cows
    Bannink, A. - \ 2007
    Wageningen University. Promotor(en): Seerp Tamminga; J. France, co-promotor(en): Jan Dijkstra. - [S.l.] : S.n. - ISBN 9789085047858 - 251
    koeien - lactatie - vluchtige vetzuren - dynamische modellen - pensfermentatie - absorptie - pensepitheel - voedingsfysiologie - celmetabolisme - cows - lactation - volatile fatty acids - dynamic models - rumen fermentation - absorption - rumen epithelium - nutrition physiology - cell metabolism
    Mathematical models are developed to quantity and integrate the various processes involved with rumen fermentation. Three extant mechanistic models of rumen fermentation were studied (Baldwin et al., Danfær and Dijkstra et al.), each with a truly dynamic representation but different conceptual approach. The models were compared on mathematical representation of individual processes and their prediction accuracy was evaluated. Although the models predicted similar rates of substrate degradation and rumen outflow of organic matter, total crude protein and microbial protein, they differed substantially in representation of the underlying microbial mechanisms. The model of Baldwin et al. performed best in prediction of the combination of rumen pool sizes and duodenal flows, whereas the model of Dijkstra et al. was evaluated to deliver the most realistic outflow of rapidly fermentable carbohydrates. Further, it was identified that all models needed improvement with respect to the prediction of amounts and type of volatile fatty acids (VFA) produced. In a subsequent evaluation is was investigated to what extent individual model elements, of a selection of five, could be responsible for inaccurate VFA predictions. The results suggested that inaccuracy of stoichiometric coefficients of VFA yield from fermented substrate (VFA coefficients) and incorrect representations of VFA absorption kinetics are the most likely causes. New values of VFA coefficients were derived by regression of a stoichiometric model of VFA yield against data of VFA molar proportions observed in vivo in rumen fluid of lactating cows. Inputs to the model were observed rates of rumen substrate degradation. Regression against simulated data sets including random error indicated that the accuracy of this method to estimate VFA coefficients is acceptable. Estimates from regressions against in vivo data delivered new sets of VFA coefficients for roughage-rich and concentrate-rich diets. In a follow-up study the representation of stoichiometry was made pH-dependent. With regression of this model against in vivo data a profound effect of rumen pH on the type of VFA formed from rapidly fermentable carbohydrates was established. Besides VFA production, the rumen concentrations and the amount and profile of VFA available for the cow are also affected by absorption and metabolism of VFA by epithelial tissues in the rumen wall. A mechanistic model was constructed that represents the dynamics of these processes, including the effects of changes in VFA concentration differences between different compartments, the effect of competitive inhibition between VFA and the effect of changes in surface area and epithelial mass. Although some essential characteristics of VFA transport and intra-epithelial metabolism could be reproduced by the model, it was concluded that there is a definite need for more experimental data. It is concluded that various levels of functioning need to be included when representing whole rumen function. Besides intrinsic degadation characteristics and passage of ingested substrates, environmental conditions in the rumen and the functionality of the rumen wall need to addressed.
    Pseudovitamin B(12) is the corrinoid produced by Lactobacillus reuteri CRL 1098 under anaerobic conditions
    Santos, F. dos; Vera, J.L. ; Lamosa, P. ; Valdez, G.F. ; Vos, W.M. de; Santos, H. ; Sesma, F. ; Hugenholtz, J. - \ 2007
    FEBS Letters 581 (2007)25. - ISSN 0014-5793 - p. 4865 - 4870.
    vitamin-b12 analogs - absorption - cobalamin - cobamide - mice
    We have reported previously on the ability of Lactobacillus reuteri to produce a compound with vitamin B-12 activity. Here we report on the chemical characterisation of this corrinoid-like molecule. High performance liquid chromatography coupled to an ultraviolet diode array detector, mass spectrometry and nuclear magnetic resonance spectroscopy has enabled us to identify the compound as Co alpha-[alpha-(7-adenyl)]-Co beta-cyanocobamide or pseudovitamin B12. This molecule differs from cobalamin in the alpha-ligand, where it has adenine instead of 5,6-dimethylbenzimidazole bound in a alpha-glycosidic linkage to C-1 of ribose. L. reuteri is the first lactic acid bacterium in which the production of a cobalamin-like molecule has been identified and the first microorganism reported to produce exclusively pseudo-B-12. (c) 2007 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
    Effects of added fermentable carbohydrates in the diet on intestinal proinflammatory cytokine-specific mRNA content in weaning piglets
    Pié, S. ; Awati, A. ; Vida, S. ; Falluel, I. ; Williams, B.A. ; Oswald, I.P. - \ 2007
    Journal of Animal Science 85 (2007). - ISSN 0021-8812 - p. 673 - 683.
    total parenteral-nutrition - lactic-acid bacteria - inflammatory responses - weanling piglets - induced colitis - growing pigs - expression - performance - absorption - prebiotics
    There is increasing evidence showing that dietary supplementation with prebiotics can be effective in the treatment of intestinal inflammation. Because weaning time is characterized by rapid intestinal inflammation, this study investigated the effect of a diet supplemented with a combination of 4 fermentable carbohydrates (lactulose, inulin, sugarbeet pulp, and wheat starch) on the mRNA content of proinflammatory cytokines in newly weaned piglets. Cytokines (IL-1ß, IL-6, IL-8, IL-12p40, IL-18, and tumor necrosis factor-) were analyzed using a semiquantitative reverse-transcription PCR technique on d 1, 4, and 10 in the ileum and colon of piglets fed either a test diet (CHO) or a control diet. In addition to the diet, the effect of enforced fasting on cytokine mRNA content was also evaluated. No effect of fasting was observed on the pro-inflammatory cytokine mRNA content. Our results showed that the CHO diet induced an up-regulation of IL-6 mRNA content in the colon of piglets 4 d postweaning. This up-regulation was specific for the animals fed the CHO diet and was not observed in animals fed the control diet. An increase in IL-1ß mRNA content was also observed on d 4 postweaning in all of the piglets. Correlations between proinflammatory cytokines and the end-products of fermentation indicated that the regulation of cytokines may be linked with some of the fermentation end-products such as branched-chain fatty acids, which are in turn end-products of protein fermentation
    Equilibrium between quenched and nonquenched conformations of the major plant light-harvesting complex studied with high-pressure time-resolved fluorescence
    Oort, B.F. van; Hoek, A. van; Ruban, A.V. ; Amerongen, H. van - \ 2007
    The Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical 111 (2007)26. - ISSN 1520-6106 - p. 7631 - 7637.
    nonphotochemical energy-dissipation - chlorophyll-protein complex - photosystem-ii - green plants - chloroplast membranes - excitation dynamics - antenna complex - molecular-basis - lhcii - absorption
    Nonphotochemical quenching (NPQ) of chlorophyll fluorescence plays an important role in the protection of plants against excessive light. Fluorescence quenching of the major light-harvesting complex (LHCII) provides a model system to study the mechanism of NPQ. The existence of both quenched and nonquenched states of LHCII has been postulated. We used time-resolved fluorescence and hydrostatic pressure to study differences between these states. Pressure shifts the thermodynamic equilibrium between the two states. The estimated volume difference was 5 mL/mol, indicating a local conformational switch. The estimated free energy difference was 7.0 kJ/mol: high enough to keep the quenched state population low under normal conditions, but low enough to switch in a controlled way. These properties are physiologically relevant properties, because they guarantee efficient light harvesting, while at the same time maintaining the capacity to switch to a quenched state. These results indicate that conformational changes of LHCII can play an important role in NPQ.
    Efficacy of iron-fortified whole maize flour on iron status of schoolchildren in Kenya: a randomised controlled trial
    Andang'o, P.E.A. ; Osendarp, S.J.M. ; Ayah, R. ; West, C.E. ; Mwaniki, D. ; Wolf, C.A. de; Kraaijenhagen, R. ; Kok, F.J. ; Verhoef, H. - \ 2007
    The Lancet 369 (2007)9575. - ISSN 0140-6736 - p. 1799 - 1806.
    plasmodium-falciparum malaria - edta nafe(iii)edta - food fortificant - missing values - elemental iron - curry powder - rapid tests - absorption - women - wheat
    Background Sodium iron edetic acid (NaFeEDTA) might be a more bioavailable source of iron than electrolytic iron, when added to maize flour. We aimed to assess the effect, on children's iron status, of consumption of whole maize flour fortified with iron as NaFeEDTA or electrolytic iron. Methods 516 children, aged 3-8 years, from four schools in Marafa, Kenya, were randomly assigned to four groups. All were given the same amount of porridge five times a week. The porridge for one group was made from unfortified whole maize flour; for the other three groups it was fortified with either high-dose NaFeEDTA (56 mg/kg), low-dose NaFeEDTA (28 mg/kg), or electrolytic iron (56 mg/kg). Concentrations of haemoglobin, plasma ferritin, and transferrin receptor were analysed in samples taken at baseline and at the end of the 5-month intervention. The primary outcome was iron-deficiency anaemia. We analysed data on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov, number NCT00386074. Findings The prevalence of iron-deficiency anaemia in children given unfortified flour was 10%. Compared with placebo, the prevalence of iron-deficiency anaemia in children given flour fortified with high-dose NaFeEDTA, low-dose NaFeEDTA, and electrolytic iron changed by -89% (95% CI -97% to -49%), -48% (-77% to 20%), and 59% (-18% to 209%), respectively. Consumption of high-dose NaFeEDTA improved all measured iron-status indicators. Low-dose NaFeEDTA decreased the prevalence of iron deficiency but did not noticeably change the prevalence of anaemia. Electrolytic iron did not improve any of these iron-status indicators. Children who were iron-deficient at baseline benefited more from high-dose and low-dose NaFeEDTA than those with sufficient iron at baseline. Interpretation Consumption of whole maize flour fortified with NaFeEDTA caused modest, dose-dependent improvements in children's iron status. Fortification with electrolytic iron did not improve their iron status. Therefore, in high-phytate flours, NaFeEDTA is more suitable than electrolytic iron for supplementation of iron in the diet.
    Hydrometeorological application of a microwave link: 1. Evaporation
    Leijnse, H. ; Uijlenhoet, R. ; Stricker, J.N.M. - \ 2007
    Water Resources Research 43 (2007). - ISSN 0043-1397 - 9 p.
    flevoland field experiment - sensible heat fluxes - heterogeneous surface - refractive-index - large-aperture - scintillometers - fluctuations - absorption - momentum - basin
    A method to estimate areal evaporation using a microwave link (radio wave scintillometer) in combination with an energy budget constraint is proposed. This radio wave scintillometry-energy budget method (RWS-EBM) is evaluated for its applicability in different meteorological conditions and for its sensitivity to various variables (the structure parameter of the refractive index of air C n 2, the total available energy R n - G, the wind velocity u, the effective average vegetation height h 0, and the correlation coefficient between the temperature and humidity fluctuations r TQ ). The method is shown to be best suited for use in wet to moderately dry conditions, where the latent heat flux is at least a third of the total available energy (i.e., Bowen ratio =2). It is important to accurately measure the total available energy and the wind velocity as the RWS-EBM is most sensitive to these variables. The Flevoland field experiment has provided the data, obtained with a 27-GHz radio wave scintillometer (over 2.2 km), a large-aperture scintillometer (also 2.2 km), and four eddy covariance systems, which are used to test the RWS-EBM. Comparing 92 daytime measurements (30-min intervals) of the evaporation estimated using the RWS-EBM to that determined in alternative manners (eddy covariance and two-wavelength scintillometry) leads to the conclusion that the method provides consistent estimates (coefficient of determination r 2 = 0.85 in both cases) under relatively wet conditions.
    The effect of NaFeEDTA on sensory perception and long term acceptance of instant noodles by Vietnamese school children
    Le, H.T. ; Joosten, M.M. ; Bijl, J. van der; Brouwer, I.D. ; Graaf, C. de; Kok, F.J. - \ 2007
    Food Quality and Preference 18 (2007)4. - ISSN 0950-3293 - p. 619 - 626.
    inter-trial variation - in-home consumption - replicated difference - iron fortification - preference tests - fish sauce - pleasantness - absorption - variety - boredom
    This study investigated the effect of NaFeEDTA fortification on taste and long term acceptance of noodles. A triangle test among 48 children (6¿8 years) and 48 adults (17¿30 years) showed that both children and adults could discriminate fortified from non-fortified noodles with and without seasoning added. A paired preference test by the same subjects with seasoned noodles showed no preference for fortified or non-fortified noodles. A long term acceptance study was carried out with 60 children randomly assigned to a monotony group and a free choice group, receiving five days a week, during 10 weeks fortified noodles with a fixed type of flavour or a flavour of own choice, respectively. Results showed a slight but significant increase of boredom over time, but acceptance ratings remained high and boredom ratings remained low throughout time in both groups. It is concluded that NaFeEDTA fortified noodles are suitable for use in food fortification programmes
    Phytate intake and molar ratios of phytate to zinc, iron and calcium in the diets of people in China
    Ma, G. ; Li, Y. ; Jin, Y. ; Zhai, F. ; Kok, F.J. ; Yang, X. - \ 2007
    European Journal of Clinical Nutrition 61 (2007). - ISSN 0954-3007 - p. 368 - 374.
    magnetic-resonance spectroscopy - vegetarian trappist monks - phytic acid - inositol phosphates - nutritional-status - millimolar ratios - absorption - bioavailability - foods - humans
    Objective: To assess the phytate intake and molar ratios of phytate to calcium, iron and zinc in the diets of people in China. Design: 2002 China Nationwide Nutrition and Health Survey is a cross-sectional nationwide representative survey on nutrition and health. The information on dietary intakes was collected using consecutive 3 days 24|[thinsp]|h recall by trained interviewers. Subjects: The data of 68|[thinsp]|962 residents aged 2|[ndash]|101 years old from 132 counties were analyzed. Results: The median daily dietary intake of phytate, calcium, iron and zinc were 1186, 338.1, 21.2 and 10.6|[thinsp]|mg, respectively. Urban residents consumed less phytate (781 vs 1342|[thinsp]|mg|[sol]|day), more calcium (374.5 vs 324.1|[thinsp]|mg|[sol]|day) and comparable amounts of iron (21.1 vs 21.2|[thinsp]|mg|[sol]|day) and zinc (10.6 vs 10.6|[thinsp]|mg|[sol]|day) than their rural counterparts. A wide variation in phytate intake among residents from six areas was found, ranging from 648 to 1433|[thinsp]|mg|[sol]|day. The median molar ratios of phytate to calcium, iron, zinc and phytate |[times]| calcium|[sol]|zinc were 0.22, 4.88, 11.1 and 89.0, respectively, with a large variation between urban and rural areas. The phytate:zinc molar ratios ranged from 6.2 to 14.2, whereas the phytate |[times]| calcium|[sol]|zinc molar ratios were from 63.7 to 107.2. The proportion of subjects with ratios above the critical values of phytate to iron, phytate to calcium, phytate to zinc and phytate |[times]| calcium|[sol]|zinc were 95.4, 43.7, 23.1 and 8.7|[percnt]|, respectively. All the phytate|[sol]|mineral ratios of rural residents were higher than that of their urban counterparts. Conclusions: The dietary phytate intake of people in China was higher than those in Western developed countries and lower than those in developing countries. Phytate may impair the bioavailability of iron, calcium and zinc in the diets of people in China
    Monitoring the stepwise phytate degradation in the upper gastrointestinal tract of pigs
    Kemme, P.A. ; Schlemmer, U. ; Mroz, Z. ; Jongbloed, A.W. - \ 2006
    Journal of the Science of Food and Agriculture 86 (2006)4. - ISSN 0022-5142 - p. 612 - 622.
    aspergillus-niger phytase - phytic acid - apparent digestibility - inositol phosphates - microbial phytase - small-intestine - plant phytase - growing pigs - dry-matter - absorption
    The degradation and formation of inositol phosphates as affected by microbial phytase and gastrointestinal enzyme activities during the passage of phytate through the stomach and small intestine were studied in two experiments with four barrows and three collection periods. The degradation and formation of inositol phosphates were measured at the duodenal and ileal sites using Cr-NDR, TiO2 and Co-EDTA as indigestible markers. In experiment 1, the effect of graded doses of Aspergillus niger phytase (0, 150 and 900 FTU Natuphos® kg-1), added to a maize-soybean meal-based diet with very low intrinsic phytase activity on the degradation of phytate and the formation of inositol phosphates during digestion in the stomach and small intestine was investigated. In experiment 2, three different mixtures of inositol phosphates, produced by Aspergillus niger phytase, containing mainly high, intermediate and low phosphorylated inositol phosphates, were added to the same maize-soybean meal-based diet as used in experiment I. The fate of the inositol phosphates during digestion in the stomach and small intestine was studied. Experiment 1 showed that the extent of phytate degradation was dependent of the graded dietary phytase activities. At high phytase activity (900 FTU kg-1 of diet), strong phytate degradation occurred and the once hydrolysed phytate was rapidly dephosphorylated to lower inositol phosphates (mainly inositol di- and triphosphates). Intermediate inositol phosphates, such as inositol tetraphosphates, were quantitatively unimportant in duodenal and ileal digesta. At a phytase activity of 150 FTU kg-1 of diet, a broader spectrum of intermediate inositol phosphates was determined, which was probably due to a slower breakdown of phytate. Experiment 2 showed as a predominant result that lower inositol phosphates such InsP4 and InsP3 were degraded, whereas InsP2 accumulated in the duodenal and ileal digesta. No substantial disappearance of phytate from the stomach and small intestine was found when high concentrations of soluble phytate were added to the diet, which indicates that no substantial phytate absorption occurs in the upper part of the pig gut.
    Effect of graded doses and a high dose of microbial phytase on the digestibility of various minerals in weaner pigs
    Kies, A.K. ; Kemme, P.A. ; Sebek, L.B.J. ; Diepen, J.T.M. van; Jongbloed, A.W. - \ 2006
    Journal of Animal Science 84 (2006)5. - ISSN 0021-8812 - p. 1169 - 1175.
    aspergillus-niger phytase - soybean-meal diet - apparent digestibility - phytic acid - young-pigs - phosphorus utilization - supplemented diets - weanling pigs - absorption - efficacy
    An experiment with 224 weaner pigs (initial BW of 7.8 kg) was conducted to determine the effect of dose of dietary phytase supplementation on apparent fecal digestibility of minerals (P, Ca, Mg, Na, K, and Cu) and on performance. Four blocks, each with 8 pens of 7 pigs, were formed. Eight dietary treatments were applied to each block in the 43-d experiment: supplementation of 0 (basal diet), 100, 250, 500, 750, 1,500, or 15,000 phytase units (FTU) or of 1.5 g of digestible P (dP; monocalcium phosphate; positive control) per kilogram of feed. The basal diet, with corn, barley, soybean meal, and sunflower seed meal as the main components, contained 1.2 g of dP per kilogram of feed. Fresh fecal grab samples were collected in wk 4 and 5 of the experiment. Average daily feed intake, ADG, G:F, and digestibility of all of the minerals increased (P <0.001) with increasing Phytase dose. Digestibility of P increased from 34% in the basal diet to a maximum of 84% in the diet supplemented with 15,000 FTU, generating 1.76 g of dP per kilogram of feed. At this level, 85% of the phytate phosphorus was digested, compared with 15% in the basal diet. Compared with the basal diet, digestibility of the monovalent minerals increased maximally at 15,000 FTU, from 81 to 92% (Na) and from 76 to 86% (K). In conclusion, phytase supplementation up to a level of 15,000 FTU/kg of a dP-deficient diet improved performance of weaner pigs and digestibility of minerals, including monovalent minerals. Up to 85% of the phytate-P was digested. Thus, dietary phytase supplementation beyond present day standards (500 FTU/kg) could further improve mineral use and consequently reduce mineral output to the environment.
    Bioavailability of Genistein and Its Glycoside Genistin As Measured in the Portal Vein of Freely Moving Unanesthetized Rats
    Steensma, A. ; Faassen, M. ; Noteborn, H.P.J.M. ; Rietjens, I.M.C.M. - \ 2006
    Journal of Agricultural and Food Chemistry 54 (2006)21. - ISSN 0021-8561 - p. 8006 - 8012.
    purified soy isoflavones - small-intestine - postmenopausal women - pharmacokinetics - absorption - cancer - glucosides - daidzein - humans - health
    The present study describes an in vivo bioavailability experiment for genistein and its glycoside genistin, either as pure compounds or from a soy protein isolate extract, using freely moving unanesthetized rats with a cannulation in the portal vein. The results show that genistein is readily bioavailable, being observed in portal vein plasma at the first point of detection at 15 min after dosing. The AUC0-24h values for total genistein and its conjugates were 54, 24, and 13 ¿M h for genistein, genistin, and an enriched protein soy extract, respectively. These results indicate that the bioavailability of genistein is higher for the aglycon than for its glycoside. Genistin is partly absorbed in its glycosidic form. It is concluded that bioavailability studies based on portal vein plasma levels contribute to insight into the role of the intestine and liver in deglycosylation and uptake characteristics of glycosylated flavonoids
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