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.

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Estimation of the in situ degradation of the washout fraction of starch by using a modified in situ protocol and in vitro measurements
Jonge, L.H. de; Laar, H. van; Dijkstra, J. - \ 2015
Animal 9 (2015)9. - ISSN 1751-7311 - p. 1465 - 1472.
dairy-cows - digestion - rumen - gas - degradability - barley - vivo - digestibility - feedstuff - cultivars
The in situ degradation of the washout fraction of starch in six feed ingredients (i.e. barley, faba beans, maize, oats, peas and wheat) was studied by using a modified in situ protocol and in vitro measurements. In comparison with the washing machine method, the modified protocol comprises a milder rinsing method to reduce particulate loss during rinsing. The modified method markedly reduced the average washout fraction of starch in these products from 0.333 to 0.042 g/g. Applying the modified rinsing method, the fractional degradation rate (k d ) of starch in barley, oats and wheat decreased from on average 0.327 to 0.144 h-1 whereas for faba beans, peas and maize no differences in k d were observed compared with the traditional washing machine rinsing. For barley, maize and wheat, the difference in non-fermented starch in the residue between both rinsing methods during the first 4 h of incubation increased, which indicates secondary particle loss. The average effective degradation of starch decreased from 0.761 to 0.572 g/g when using the new rinsing method and to 0.494 g/g when applying a correction for particulate matter loss during incubation. The in vitro k d of starch in the non-washout fraction did not differ from that in the total product. The calculated ratio between the k d of starch in the washout and non-washout fraction was on average 1.59 and varied between 0.96 for oats and 2.39 for maize. The fractional rate of gas production was significantly different between the total product and the non-washout fraction. For all products, except oats, this rate of gas production was larger for the total product compared with the non-washout fraction whereas for oats the opposite was observed. The rate of increase in gas production was, especially for grains, strongly correlated with the in vitro k d of starch. The results of the present study do not support the assumption used in several feed evaluation systems that the degradation of the washout fraction of starch in the rumen is much faster than that of the non-washout fraction.
Convergence of European wheat yields
Powell, J.P. ; Rutten, M.M. - \ 2013
Renewable and Sustainable Energy Reviews 28 (2013). - ISSN 1364-0321 - p. 53 - 70.
agricultural land-use - panel-data - model - productivity - estimators - regression - scenarios - emissions - gas
The paper makes several contributions to the study of wheat yield changes in Europe and the resulting economic consequences in the near to medium term future. In particular, it addresses the issue of the effects of yield changes on land use. The transition and growth of yields are estimated using a combination of convergence, time-series and dynamic panel models. Scenarios are then run using estimated yields as input into a computable general equilibrium (CGE) model. The CGE model provides a narrative framework through which the total economic impact of changes in yields can be analyzed. Together, the complementary approaches of econometrics and general equilibrium models allow a more complete economic analysis of the consequences of yield changes for this important biofuels crop to emerge. Although there is no evidence of a common rate of yield convergence across Europe, there is evidence of absolute convergence. Standard time series and panel forecasting methods indicate the potential for only very modest yearly yield increases across most of Europe given optimistic assumptions; although potential yearly increases in newer European states could, in some cases, be substantially higher. However, the total amount of land released as a result of potential yield increases in the wheat sector is only modest because of an increase in demand for land by sectors other than wheat. The overall question of whether significant yield increases will necessarily lead to large increases in land available to produce bio-energy crops is rejected. Land freed by wheat yield increases will go to the production of a wide range of agricultural products that value it as an input. The same reasoning which links yields and land use applies to all agricultural products when there are well functioning markets. (C) 2013 Elsevier Ltd. All rights reserved.
Processing Technologies and Cell Wall Degrading Enzymes To Improve Nutritional Value of Dried Distillers Grain with Solubles for Animal Feed: an in Vitro Digestion Study
Vries, S. de; Pustjens, A.M. ; Kabel, M.A. ; Salazar-Villanea, S. ; Hendriks, W.H. ; Gerrits, W.J.J. - \ 2013
Journal of Agricultural and Food Chemistry 61 (2013)37. - ISSN 0021-8561 - p. 8821 - 8828.
amino-acid - dietary fiber - growing pigs - nonstarch polysaccharides - corn - fermentation - gas - ingredients - ethanol - digestibility
Currently, the use of maize dried distillers grain with solubles (DDGS) as protein source in animal feed is limited by the inferior protein quality and high levels of non-starch polysaccharides (NSP). Processing technologies and enzymes that increase NSP degradability might improve digestive utilization of DDGS, enhancing its potential as a source of nutrients for animals. The effects of various combinations of processing technologies and commercial enzyme mixtures on in vitro digestion and subsequent fermentation of DDGS were tested. Wet-milling, extrusion, and mild hydrothermal acid treatment increased in vitro protein digestion but had no effect on NSP. Severe hydrothermal acid treatments, however, effectively solubilized NSP (48–78%). Addition of enzymes did not affect NSP solubilization in unprocessed or processed DDGS. Although the cell wall structure of DDGS seems to be resistant to most milder processing technologies, in vitro digestion of DDGS can be effectively increased by severe hydrothermal acid treatments.
In vitro fermentation of 12 dietary fibres by faecal inoculum from pigs and humans
Jonathan, M.C. ; Borne, J.J.G.C. van den; Wiechen, P. van; Souza Da Silva, C. ; Schols, H.A. ; Gruppen, H. - \ 2012
Food Chemistry 133 (2012)3. - ISSN 0308-8146 - p. 889 - 897.
gastrointestinal-tract - colonic function - fatty-acids - polysaccharides - kinetics - starch - gas - fermentability - chromatography - degradation
In vitro fermentation of twelve dietary fibers by fecal inocula from pigs and humans were performed. The fibers included homoglucans, mannans, fructans, polyuronides, and complex heteroglycans. Gas production, short chain fatty acid production and fiber degradation products were monitored during fermentation. Human inoculum has more ability to ferment resistant starch and fibers containing uronic acids. In contrast, pig inoculum is able to ferment cellulose, which is hardly fermented by human inoculum. The sugar and linkage composition of the fibers has an important influence on fiber fermentation patterns. Fibers containing uronic acids induced the production of acetate, whereas fibers containing neutral sugars induced the production of propionate or butyrate. Fermentation of the fructans showed that molecular size could be an influential factor, and fermentation of complex heteroglycans showed that the arrangement of sugars in the molecules may also affect the fermentation patterns. This experiment also shows that monitoring of fiber degradation products is important for understanding how fibers are degraded during fermentation.
Combinatorial Life Cycle Assessment to Inform Process Design of Industrial Production of Algal Biodiesel
Brentner, L.B. ; Eckelman, M.J. ; Zimmerman, J.B. - \ 2011
Environmental Science and Technology 45 (2011). - ISSN 0013-936X - p. 7060 - 7067.
supercritical co2 - microalgae - bioreactors - extraction - chitosan - energy - gas - photobioreactors - flocculation - cultivation
The use of algae as a feedstock for biodiesel production is a rapidly growing industry, in the United States and globally. A life cycle assessment (LCA) is presented that compares various methods, either proposed or under development, for algal biodiesel to inform the most promising pathways for sustainable full-scale production. For this analysis, the system is divided into five distinct process steps: (1) microalgae cultivation, (2) harvesting and/or dewatering, (3) lipid extraction, (4) conversion (transesterification) into biodiesel, and (5) byproduct management. A number of technology options are considered for each process step and various technology combinations are assessed for their life cycle environmental impacts. The optimal option for each process step is selected yielding a best case scenario, comprised of a flat panel enclosed photobioreactor and direct transesterification of algal cells with supercritical methanol. For a functional unit of 10 GJ biodiesel, the best case production system yields a cumulative energy demand savings of more than 65 GJ, reduces water consumption by 585 m3 and decreases greenhouse gas emissions by 86% compared to a base case scenario typical of early industrial practices, highlighting the importance of technological innovation in algae processing and providing guidance on promising production pathways.
Assessment of two complementary liquid chromatography coupled to high resolution mass spectrometry metabolomics strategies for the screening of anabolic steroid treatment in calves
Dervilly-Pinel, G. ; Weigel, S. ; Lommen, A. ; Chereau, S. ; Rambaud, L. ; Essers, M.L. ; Antignac, J.P. ; Nielen, M.W.F. ; Bizec, B. Le - \ 2011
Analytica Chimica Acta 700 (2011)1-2. - ISSN 0003-2670 - p. 144 - 154.
human urine - bovine urine - nandrolone metabolites - gas - cattle - metabonomics - hair - 19-norandrosterone - 19-nortestosterone - 17-beta-estradiol
Anabolic steroids are banned in food producing livestock in Europe. Efficient methods based on mass spectrometry detection have been developed to ensure the control of such veterinary drug residues. Nevertheless, the use of “cocktails” composed of mixtures of low amounts of several substances as well as the synthesis of new compounds of unknown structure prevent efficient prevention. New analytical tools able to detect such abuse are today mandatory. In this context, metabolomics may represent new emerging strategies for investigating the global physiological effects associated to a family of substances and therefore, to suspect the administration of steroids. The purpose of the present study was to set up, assess and compare two complementary mass spectrometry-based metabolomic strategies as new tools to screen for steroid abuse in cattle and demonstrate the feasibility of such approaches. The protocols were developed in two European laboratories in charge of residues analysis in the field of food safety. Apart from sample preparation, the global process was different in both laboratories from LC-HRMS fingerprinting to multivariate data analysis through data processing and involved both LC-Orbitrap-XCMS and UPLC-ToF-MS-MetAlign strategies. The reproducibility of both sample preparation and MS measurements were assessed in order to guarantee that any differences in the acquired fingerprints were not caused by analytical variability but reflect metabolome modifications upon steroids administration. The protocols were then applied to urine samples collected on a large group of animals consisting of 12 control calves and 12 calves administrated with a mixture of 17ß-estradiol 3-benzoate and 17ß-nandrolone laureate esters according to a protocol reflecting likely illegal practices. The modifications in urine profiles as indicators of steroid administration have been evaluated in this context and proved the suitability of the approach for discriminating anabolic treated animals from control ones. Such an approach may therefore open a new way for the screening of anabolic steroid administration through targeted monitoring of relevant biomarkers highlighted as a result of the metabolomics study.
Investigation of urinary steroid metabolites in calf urine after oral and intramuscular administration of DHEA
Becue, I. ; Poucke, C. ; Rijk, J.C.W. ; Bovee, T.F.H. ; Nielen, M.W.F. ; Peteghem, C. van - \ 2010
Analytical and Bioanalytical Chemistry 396 (2010)2. - ISSN 1618-2642 - p. 799 - 808.
mass-spectrometry - androgen profile - dehydroepiandrosterone - gas - consequences - prohormones - supplements - bioassay - men
DHEA (3ß-hydroxy-androst-5-en-17-one) is a natural steroid prohormone. Despite a lack of information on the effect, DHEA and other prohormones are frequently used as a food supplement by body-builders. DHEA is suspected for growth promoting abuse in cattle as well. Considering the latter, urine samples from a previous exposure study in which calves were exposed to 1 g DHEA per day for 7 days, were used. The calves were divided in three groups: one orally treated, one intramuscularly injected, and a control group. The effect of this treatment on the urinary profile of several precursors and metabolites of DHEA was investigated. Urine samples were collected several days before and during the 7 days of administration and were submitted to a clean-up procedure consisting of a separation of the different conjugates (free, glucuronidated, and sulfated forms) of each compound on a SAX column (Varian). An LC-MS/MS method was developed for the detection and quantification of several metabolites of the pathway of DHEA including 17a- and 17ß-testosterone, 4-androstenedione, 5-androstenediol, pregnenolone, and hydroxypregnenolone. Elevated levels of DHEA, 5-androstenediol, and 17a-testosterone were observed in the free and sulfated fraction of the urine of the treated calves, thus indicating that the administered DHEA is metabolized mainly by the ¿5-pathway with 5-androstenediol as the intermediate. Sulfoconjugates of DHEA and its metabolites were found to constitute the largest proportion of the urinary metabolites. The free form was also present, but in a lesser extent than the sulfated form, while glucuronides were negligible.
Updated Abraham solvation parameters for polychlorinated biphenyls
Noort, P.C.M. van; Haftka, J.J.H. ; Parsons, J.R. - \ 2010
Environmental Science and Technology 44 (2010)18. - ISSN 0013-936X - p. 7037 - 7042.
carbon/water partition-coefficients - polycyclic aromatic-hydrocarbons - sodium dodecyl-sulfate - henrys law constants - physicochemical properties - aqueous solubilities - energy relationships - water - phase - gas
This study shows that the recently published polychlorinated biphenyl (PCB) Abraham solvation parameters predict PCB air-n-hexadecane and n-octanol-water partition coefficients very poorly, especially for highly ortho-chlorinated congeners. Therefore, an updated set of PCB solvation parameters was derived from four PCB properties and associated Abraham solvation equations. Additionally, the influence of ortho-chlorination on PCB solvent accessible volume and surface area was investigated. The updated PCB solvation parameters were tested on partitioning between five other phase combinations. Compared to the original PCB solvation parameter set, the updated PCB solvation parameters resulted in substantially improved estimates from Abraham solvation equations for (subcooled) liquid vapor pressures, aqueous solubilities, HPLC capacity factors, and for coefficients of air-n-hexadecane, air-water, organic carbon-water, and n-octanol-water partitioning. For water to polydimethyl siloxane and sodium dodecylsulphate (SDS) partitioning, the updated PCB solvation parameters yielded no improvement compared to the original data set. The main difference between the updated and the original parameter set is that updated PCB McGowan specific volumes depend on the degree of ortho-chlorination, which is qualitatively confirmed by trends in the PCB solvent accessible volumes and surface areas. The use of the updated PCB solvation parameters instead of the original values is therefore recommended
Elimination kinetic of 17B-estradiol 3-benzoate and 17B-nandrolone laureate ester metabolites in calves' urine
Pinel, G. ; Rambaud, L. ; Cacciatore, G. ; Bergwerff, A. ; Elliott, C. ; Nielen, M.W.F. - \ 2008
Journal of Steroid Biochemistry and Molecular Biology 110 (2008)1-2. - ISSN 0960-0760 - p. 30 - 38.
tandem mass-spectrometry - anabolic-steroids - bovine urine - nandrolone metabolites - gas - 19-nortestosterone - confirmation - residues - cattle - horse
Efficient control of the illegal use of anabolic steroids must both take into account metabolic patterns and associated kinetics of elimination; in this context, an extensive animal experiment involving 24 calves and consisting of three administrations of 17 beta-estradiol 3-benzoate and 17 beta-nandrolone laureate esters was carried out over 50 days. Urine samples were regularly collected during the experiment from all treated and non-treated calves. For sample preparation, a single step high throughput protocol based on 96-well C-18 SPE was developed and validated according to the European Decision 2002/657/EC requirements. Decision limits (CC alpha) for steroids were below 0.1 mu g L-1, except for 19-norandrosterone (CC alpha = 0.7 mu g L-1) and estrone (CC alpha = 0.3 mu g L-1). Kinetics of elimination of the administered 17 beta-estradiol 3-benzoate and 17 beta-nandrolone laureate were established by monitoring 17 beta-estradiol, 17 alpha-estradiol, estrone and 17 beta-nandrolone, 17 alpha-nandrolone, 19-noretiocholanolone, 19-norandrostenedione, respectively. All animals demonstrated homogeneous patterns of elimination both from a qualitative (metabolite profile) and quantitative point of view (elimination kinetics in urine). Most abundant metabolites were 17 alpha-estradiol and 17 alpha-nandrolone (> 20 and 2 mg L-1, respectively after 17 beta-estradiol 3-benzoate and 17 beta-nandrolone laureate administration) whereas 17 beta-estradiol, estrone, 17 beta-nandrolone, 19-noretiocholanolone and 19-norandrostenedione were found as secondary metabolites at concentration values up to the mu g L-1 level. No significant difference was observed between male and female animals. The effect of several consecutive injections on elimination profiles was studied and revealed a tendency toward a decrease in the biotransformation of administered steroid 17 beta form. (c) 2008 Elsevier Ltd. All rights reserved.
Acid-base balance of umbilical artery blood of liveborn piglets at birth and its relation with factors affecting delivery of individual piglets
Dijk, A.D.J. van; Lende, T. van der; Taverna, M.A. - \ 2006
Theriogenology 66 (2006)8. - ISSN 0093-691X - p. 1824 - 1833.
newborn piglets - perinatal mortality - parturition - viability - gas - pig - asphyxia - analyzer - ph - stillbirth
In the limited number of studies that reported on the relation between factors affecting birth of individual piglets and acid-base balance values at birth, predominantly simple correlation coefficients have been used. The aim of the present study was to analyse the relation between factors affecting delivery of individual liveborn piglets and acid-base balance values (pH, P-CO2, HCO3- and BEecf) at birth. In total 201 piglets originating from 44 litters were used for the collection of blood samples from the umbilical artery immediately after birth, preferably in the period of apnea. Blood samples were analysed with the iStat (R) Portable Clinical Analyser. Significantly lower pH, HCO3-, BEecf and significantly higher P-CO2 levels were found in posteriorly presented piglets, independently of the condition of the umbilical cord, birth weight and cumulative birth interval/rank. Independently of presentation, birth weight and rank, piglets born with ruptured umbilical cords showed significantly lower pH values. Next to that, increasing birth weights resulted in increasing HCO3- and BEecf values at birth, independently of presentation, condition of the umbilical cord and cumulative birth interval/rank. Both an increase in cumulative birth interval and in rank was associated with a significant decrease of pH, HCO3-, BEecf and increase of P-CO2 levels in umbilical cord blood at birth. Together these results demonstrate for the first time that a clear relation exists between (factors affecting) the progress of delivery and acid-base balance values in a polytocous species like the pig. (c) 2006 Elsevier Inc. All rights reserved.
Carbon monoxide conversion by thermophilic sulfate-reducing bacteria in pure culture and in co-culture with Carboxydothermus hydrogenoformans
Parshina, S.N. ; Kijlstra, S. ; Henstra, A.M. ; Sipma, J. ; Plugge, C.M. ; Stams, A.J.M. - \ 2005
Applied Microbiology and Biotechnology 68 (2005)3. - ISSN 0175-7598 - p. 390 - 396.
desulfovibrio-vulgaris hildenborough - anaerobic bioreactor sludges - sp-nov - gen.-nov. - methanogenic bacteria - growth - reduction - energy - gas - hydrogenases
Biological sulfate (SO4) reduction with carbon monoxide (CO) as electron donor was investigated. Four thermophilic SO4-reducing bacteria, Desulfotomaculum thermoacetoxidans (DSM 5813), Thermodesulfovibrio yellowstonii (ATCC 51303), Desulfotomaculum kuznetsovii (DSM 6115; VKM B-1805), and Desulfotomaculum thermobenzoicum subsp. thermosyntrophicum (DSM 14055), were studied in pure culture and in co-culture with the thermophilic carboxydotrophic bacterium Carboxydothermus hydrogenoformans (DSM 6008). D. thermoacetoxidans and T. yellowstonii were extremely sensitive to CO: their growth on pyruvate was completely inhibited at CO concentrations above 2% in the gas phase. D. kuznetsovii and D. thermobenzoicum subsp. thermosyntrophicum were less sensitive to CO. In pure culture, D. kuznetsovii and D. thermobenzoicum subsp. thermosyntrophicum were able to grow on CO as the only electron donor and, in particular in the presence of hydrogen/carbon dioxide, at CO concentrations as high as 50-70%. The latter SO4 reducers coupled CO oxidation to SO4 reduction, but a large part of the CO was converted to acetate. In co-culture with C. hydrogenoformans, D. kuznetsovii and D. thermobenzoicum subsp. thermosyntrophicum could even grow with 100% CO (P CO=120 kPa).
Kinetics of the reaction between dissolved sodium sulfide and biologically produced sulfur
Kleinjan, W.E. ; Keizer, A. de; Janssen, A.J.H. - \ 2005
Industrial & Engineering Chemistry Research 44 (2005)2. - ISSN 0888-5885 - p. 309 - 317.
elemental sulfur - polysulfide ions - hydrogen-sulfide - aqueous sulfide - oxidation - desulfurization - equilibrium - particles - water - gas
The kinetics of the heterogeneous reaction between dissolved sodium sulfide and biologically produced sulfur particles has been studied by measuring the formation of polysulfide ions, Sx2-, in time (pH = 8.0, T = 30-50 °C). Detailed knowledge of this reaction is essential to understand its effect on a biotechnological hydrogen sulfide removal process. The data were fitted with a reaction rate model in which heterogeneous reaction kinetics, decreasing particle size, and a nonuniform particle size distribution were incorporated. Polysulfide ions formed in this reaction have an autocatalytic effect. The observed reaction rate of the autocatalyzed reaction is limited by chemical reaction, contrary to earlier reports for the reaction of sulfide with "inorganic" granular sulfur, which was diffusion-rate-limited. The small particle size or the specific hydrophilic surface properties probably make the surface of the biologically produced sulfur particles more easily available for reaction than the surface of granular sulfur.
Quantification of physical properties of dredged sediments during physical ripening
Vermeulen, J. ; Dijk, S.G. ; Grotenhuis, J.T.C. ; Rulkens, W.H. - \ 2005
Geoderma 129 (2005)3-4. - ISSN 0016-7061 - p. 147 - 166.
marine clay soil - hydraulic conductivity - modeling diffusion - unsaturated soils - oxygen diffusion - aggregate size - bulk-density - shrinkage - gas - denitrification
The soil formation process ripening can be used as a bioremediation technique for dredged sediments that are polluted with organic chemicals. Currently, data are lacking that quantify the effects of physical ripening on parameters that affect aerobic bioremediation. We quantified the effects of physical ripening on shrinkage, swelling, moisture retention, hydraulic conductivity, and oxygen diffusion for three freshly dredged sediments using specially designed pressure chambers. We also quantified the effect of physical ripening on structure development by measuring aggregate size distributions for four half-ripe and four ripe sediment samples that were collected from field sediment disposal sites. The course of physical ripening and the aerobic bioremediation process for sediments at above ground (upland) disposal sites can be predicted using the data and information developed in this study when using a combination of existing water and oxygen transport and ripening models
Doppler-free two-photon spectroscopy on the S1 ¿ S0 origin band of 1,4-diazabicyclo[2,2,2]octane (DABCO)
Berden, J.A. ; Groot, T.T. ; Veldt, T. van der; Meijer, G. - \ 1997
Chemical Physics Letters 265 (1997)1-2. - ISSN 0009-2614 - p. 204 - 208.
vanderwaals complexes - electronic-spectra - transitions - molecules - benzene - fluorescence - state - gas
The rotationally resolved two-photon excitation spectrum of the Q-branch (¿J = 0) of the O00 band in the S1 ¿ S0 transition of DABCO was recorded in a cell at room temperature. Two counterpropagating narrow bandwidth laser beams were used for Doppler-free excitation. The observed linewidth was 20 MHz. Analysis of the spectra provides the change upon electronic excitation of the rotational constants.
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