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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    Influence of phenylacetic acid pulses on anaerobic digestion performance and archaeal community structure in WWTP sewage sludge digesters
    Cabrol, L. ; Urra, J. ; Rosenkranz, F. ; Kroff, P.A. ; Plugge, C.M. ; Lesty, Y. ; Chamy, R. - \ 2015
    Water Science and Technology 71 (2015)12. - ISSN 0273-1223 - p. 1790 - 1799.
    rioolslib - anaërobe behandeling - anaërobe afbraak - sewage sludge - anaerobic treatment - anaerobic digestion - waste-water treatment - olive mill wastewaters - volatile fatty-acids - 16s ribosomal-rna - biogas production - degradation efficiency - microbial-populations - aromatic-compounds - phenolic-compounds - inhibition
    The effect of phenylacetic acid (PAA) pulses on anaerobic digestion (AD) performance and archaeal community structure was evaluated in anaerobic digesters treating sewage sludge from a wastewater treatment plant (WWTP). Four pilot-scale continuous stirred tank reactors were set up at a full-scale municipal WWTP in Santiago de Chile, and fed with either primary or mixed sewage sludge. AD performance was evaluated by volatile fatty acid (VFA) and biogas production monitoring. Archaeal community structure was characterized by 16S rRNA denaturing gradient gel electrophoresis and band sequencing. In the primary sludge digester, a single PAA pulse at 200 mg L(-1) was sufficient to affect AD performance and archaeal community structure, resulting in long-term VFA accumulation, reduced biogas production and community shift from dominant acetoclastic (Methanosaeta concilii) to hydrogenotrophic (Methanospirillum hungatei) methanogens. By contrast, AD performance and archaeal community structure in the mixed sludge digester were stable and resistant to repeated PAA pulses at 200 and 600 mg L(-1). This work demonstrated that the effect of PAA pulses on methanogenic activity and archaeal community structure differed according to AD substrate, and suggests that better insights of the correlations between archaeal population dynamics and functional performance could help to better face toxic shocks in AD
    Healthy virgin olive oil: a matter of bitterness
    Vitaglione, P. ; Savarese, M. ; Paduano, A. ; Scalfi, L. ; Fogliano, V. ; Sacchi, R. - \ 2015
    Critical Reviews in Food Science and Nutrition 55 (2015)13. - ISSN 1040-8398 - p. 1808 - 1818.
    regulated deficit irrigation - olea-europaea l. - phenolic-compounds - antioxidant activity - sensory properties - heart-disease - hydrophilic antioxidants - secoiridoid derivatives - malaxation temperature - biological-activities
    Virgin olive oil (VOO) is the pillar fat of Mediterranean diet. It is made from olive fruits and obtained by squeezing olives without any solvent extraction. Respect to the seed oils, an unique polar polyphenol-rich fraction gives to VOO a bitter and pungent taste. The recent substantiation by European Food Safety Authority (EFSA) of a health claim for VOO polyphenols, may represent an efficient stimulus to get the maximum health benefit from one of the most valuable traditional product of Mediterranean countries educating consumers to the relationship between the VOO bitterness and its health effect. Agronomical practices and new processing technology to avoid phenolic oxidation and hydrolysis and to enhance the aromatic components of the VOO have been developed and they can be used to modulate taste and flavour to diversify the products on the market. VOOs having high concentration of phenol compounds are bitter and pungent therefore many people do not consume them, thus loosing the health benefits related to their intake. In this paper the chemist's and nutritionist's points of view have been considered to address possible strategies to overcome the existing gap between the quality perceived by consumer and that established by expert tasters. Educational campaigns emphasizing the bitter-health link for olive oils should be developed.
    Characterization of Conventional, Biodynamic, and Organic Purple Grape Juices by Chemical Markers, Antioxidant Capacity, and Instrumental Taste Profile
    Granato, D. ; Margraf, T. ; Brotzakis, I. ; Capuano, E. ; Ruth, S.M. van - \ 2015
    Journal of Food Science 80 (2015)1. - ISSN 0022-1147 - p. C55 - C65.
    phenolic-compounds - agricultural practices - oxidative stress - fruit juices - geographical origin - polyphenol content - electronic tongue - tomato juices - red wines - chemometrics
    The objectives of this study were to characterize organic, biodynamic, and conventional purple grape juices (n = 31) produced in Europe based on instrumental taste profile, antioxidant activity, and some chemical markers and to propose a multivariate statistical model to analyze their quality and try to classify the samples from the 3 different crop systems. Results were subjected to ANOVA, correlation, and regression analysis, principal component analysis (PCA), hierarchical cluster analysis (HCA), soft independent modeling of class analogy (SIMCA), and partial least-squares discriminant analysis (PLSDA). No statistical significant differences (P > 0.05) were observed among juices from the 3 crop systems. Using PCA and HCA, no clear separation among crop systems was observed, corroborating the ANOVA data. However, PCA showed that the producing region highly affects the chemical composition, electronic tongue parameters, and bioactivity of grape juices. In this sense, when organic and biodynamic were grouped as “nonconventional” juices, SIMCA model was able to discriminate 12 out of 13 organic/biodynamic juices and 17 out of 18 conventional juices, presenting an efficiency of 93.5%, while 11 out of 13 non-conventional and 100% conventional grape juices were correctly classified using PLSDA. The use of electronic tongue and the determination of antioxidant properties and major phenolic compounds have shown to be a quick and accurate analytical approach to assess the quality of grape juices.
    Pearling barley to alter the composition of the raw material before brewing
    Donkelaar, L.H.G. van; Noordman, T.R. ; Boom, R.M. ; Goot, A.J. van der - \ 2015
    Journal of Food Engineering 150 (2015). - ISSN 0260-8774 - p. 44 - 49.
    hull-less barley - liquid-chromatography - phenolic-compounds - hordeum-vulgare - rich fractions - alpha-amylase - malt extracts - dietary fiber - quality - components
    Partly replacing malt with unmalted barley is a trend in brewing. The use of unmalted barley, however, leads to issues such as haze and high mash viscosity, due to its higher content of undesired components. Pearling, an abrasive method to remove the outer layers of the barley kernels has been shown to reduce the content of insoluble fibre, ash, protein and polyphenols; the ß-amylase activity and starch content of the remaining kernel were hardly affected. Removing the outer 5% of the kernel, for example, results in a 15% reduction of insoluble arabinoxylans, 23% of the insoluble fibre content and 25% of the water holding capacity of the non-starch components. It also reduces the ash content by 19% and the polyphenol content by 11%, but only 0.20% of the starch is pearled off. A relation was found between the insoluble fibre content and the water holding capacity of a fraction. Lower fibre content reduces the water holding capacity and thus the volume of the spent grains, which implies that less wort and sugar are lost during filtration. In addition, that the bran fraction remains dry, implies a reduction in energy required to dry the spent grains.
    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.
    Radical-Scavenging Compounds from Olive Tree (Olea europaea L.) wood
    Pérez-Bonilla, M. ; Salido, S. ; Beek, T.A. van; Altarejos, J. - \ 2014
    Journal of Agricultural and Food Chemistry 62 (2014)1. - ISSN 0021-8561 - p. 144 - 151.
    solid-phase extraction - antioxidant activity - phenolic-compounds - complex-mixtures - pruning biomass - potential uses - food-industry - plants - hplc - identification
    The purpose of this study was to complete knowledge on the chemical composition and radical-scavenging activity of olive tree wood. Two new monoterpene glycosides, (-)-oleuropeic acid 6'-O-a-d-glucopyranosyl ester (6a) and (-)-perillic acid 1'-O-ß-d-primeverosyl ester (8), together with the known compounds (-)-oleuropeic acid (1), (-)-olivil (2), the aldehydic form of oleuropein aglycone (3), (+)-1-hydroxypinoresinol 1-O-ß-d-glucopyranoside (4), (-)-oleuropeic acid 1'-O-ß-d-glucopyranosyl ester (5), (-)-oleuropeic acid 6'-O-ß-d-glucopyranosyl ester (6b), and (-)-olivil 4-O-ß-d-glucopyranoside (7) were isolated from an ethyl acetate extract. The radical scavengers found (2–4 and 7) were detected and isolated with the help of the online HPLC-DAD-DPPH/ABTS technique. Compounds 2–4 and 7 displayed a higher antioxidative effect against the free radical DPPH than the reference BHT and lower than hydroxytyrosol, whereas compounds 1, 5, 6a, 6b, and 8 showed no activity.
    Release of Antioxidant Capacity from Five Plant Foods during a Multistep Enzymatic Digestion Protocol
    Papillo, V.A. ; Vitaglione, P. ; Graziani, G. ; Gokmen, V. ; Fogliano, V. - \ 2014
    Journal of Agricultural and Food Chemistry 62 (2014)18. - ISSN 0021-8561 - p. 4119 - 4126.
    in-vitro digestion - dietary fiber - phaseolus-vulgaris - phenolic-compounds - whole grains - risk - health - polyphenols - phytochemicals - quality
    This study aimed at elucidating the influence of food matrix on the release of antioxidant activity from five plant foods (apple, spinach, walnut, red bean, and whole wheat). To this purpose a protocol based on sequential enzymatic digestion was adopted. The total antioxidant capacity (TAC) of both solubilized and insoluble materials was measured at each step. Results showed that the overall TAC obtained by enzyme treatments was usually higher than that obtained by chemical extraction-based methods. In apple most of the TAC was released upon water washing and after pepsin treatment, whereas in spinach, beans, and whole wheat the TAC released by treatments with bacterial enzymes was prominent. Walnut had the highest TAC value, which was mainly released after pancreatin treatment. Therefore, the enzyme treatment is fundamental to estimate the overall potential TAC of foods having a high amount of polyphenols bound to dietary fiber or entrapped in the food matrix.
    Targeted metabolite profile of food bioactive compounds by Orbitrap high resolution mass spectrometry: The 'FancyTiles' approach
    Troise, A.D. ; Ferracane, R. ; Palermo, M. ; Fogliano, V. - \ 2014
    Food Research International 63 (2014). - ISSN 0963-9969 - p. 139 - 146.
    virgin olive oil - cynara-scolymus l. - performance liquid-chromatography - artichoke leaf extract - time-of-flight - phenolic-compounds - sesquiterpene lactones - biological-activities - antioxidant capacity - sensory properties
    In this paper a new targeted metabolic profile approach using Orbitrap high resolution mass spectrometry was described. For each foodmatrix various classes of bioactive compounds and some specificmetabolites of interest were selected on the basis of the existing knowledge creating an easy-to-read fingerprinting named “FancyTiles”. The procedure resulted in a plot of semi-quantitative data allowed to highlight for each food the main metabolites related to the biological or sensorial attributes within an educated schema. Results showed that the FancyTile procedure is a useful tool for research programs aiming at improving the health potential of food and ingredients. In this paper the FancyTilewas described and it was successfully applied to verify the differences in themetabolic profile. Olive oils from different cultivars,waste millwaters fromolive grown in different location and artichokes cultivated with different agronomical practices were used as case study.
    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.
    Metabolic diversity in apple germplasm
    Khan, S.A. ; Tikunov, Y.M. ; Chibon, P.Y.F.R.P. ; Maliepaard, C.A. ; Beekwilder, M.J. ; Jacobsen, E. ; Schouten, H.J. - \ 2014
    Plant Breeding 133 (2014)2. - ISSN 0179-9541 - p. 281 - 290.
    x domestica borkh. - linkage group 16 - phenolic-compounds - genetic diversity - malus-sieversii - mqtl hotspot - rosaceae - origin - fruits - genome
    We analysed metabolic diversity in apples from wild species, elite material and a F1 population, using liquid chromatography–mass spectrometry (LC-QTOF-MS). The evaluated elite material appeared to have strongly reduced levels of phenolic compounds, down to 1% of the concentrations in the investigated wild germplasm. In one quarter of the F1 population, the concentrations of phenolic compounds such as quercetin derivatives, procyanidin, catechin and epicatechin were further significantly reduced, due to accumulation of recessive alleles of putatively leucoanthocyanidin reductase, a structural gene that is located at the top of LG16. In another part of F1 progeny, putatively glycosylated forms of ß-glycols were up to 50 times more abundant compared to both parents. These metabolites were mapped with high logarithm of odds (LOD) scores at the top of LG8, and progeny that was homozygous recessive for the candidate gene showed the elevated levels. We hypothesize that this was caused by inheritance of non-functional alleles of enoyl-CoA hydratase gene. Both examples of
    Bitter Taste Receptor Activation by Flavonoids and Isoflavonoids: Modeled Structural Requirements for Activation of hTAS2R14 and hTAS2R39
    Roland, W.S.U. ; Buren, R.G.C. van; Gruppen, H. ; Driesse, M. ; Gouka, R.J. ; Smit, G. ; Vincken, J.P. - \ 2013
    Journal of Agricultural and Food Chemistry 61 (2013)44. - ISSN 0021-8561 - p. 10454 - 10466.
    phenolic-compounds - peptides activate - chemistry - health
    Many flavonoids and isoflavonoids have an undesirable bitter taste, which hampers their use as food bioactives. The aim of this study was to investigate the effect of a large set of structurally similar (iso)flavonoids on the activation of bitter receptors hTAS2R14 and hTAS2R39 and to predict their structural requirements to activate these receptors. In total, 68 compounds activated hTAS2R14 and 70 compounds activated hTAS2R39, among which 58 ligands were overlapping. Their activation threshold values varied over a range of 3 log units between 0.12 and 500 µM. Ligand-based 2D-fingerprint and 3D-pharmacophore models were created to detect structure–activity relationships. The 2D models demonstrated excellent predictive power in identifying bitter (iso)flavonoids and discrimination from inactive ones. The structural characteristics for an (iso)flavonoid to activate hTAS2R14 (or hTAS2R39) were determined by 3D-pharmacophore models to be composed of two (or three) hydrogen bond donor sites, one hydrogen bond acceptor site, and two aromatic ring structures, of which one had to be hydrophobic. The additional hydrogen bond donor feature for hTAS2R39 ligands indicated the possible presence of another complementary acceptor site in the binding pocket, compared to hTAS2R14. Hydrophobic interaction of the aromatic feature with the binding site might be of higher importance in hTAS2R14 than in hTAS2R39. Together, this might explain why OH-rich compounds showed different behaviors on the two bitter receptors. The combination of in vitro data and different in silico methods created a good insight in activation of hTAS2R14 and hTAS2R39 by (iso)flavonoids and provided a powerful tool in the prediction of their potential bitterness. By understanding the “bitter motif”, introduction of bitter taste in functional foods enriched in (iso)flavonoid bioactives might be avoided.
    Soluble Antioxidant Compounds Regenerate the Antioxidants Bound to Insoluble Parts of Foods
    Celik, E.E. ; Gökmen, V. ; Fogliano, V. - \ 2013
    Journal of Agricultural and Food Chemistry 61 (2013)43. - ISSN 0021-8561 - p. 10329 - 10334.
    dietary fiber - phenolic-compounds - health - capacity
    This study aimed to investigate the regeneration potential of antioxidant capacity of an insoluble food matrix. Investigations were performed in vitro with several food matrices rich in dietary fiber (DF) and bound antioxidants. After removal of the soluble fraction, the antioxidant capacity (AC) of the insoluble fraction was measured by the QUENCHER procedure using ABTS(•+) or DPPH(•) radicals. After measurement, the insoluble residue was washed out to remove the excess of radicals and treated with pure antioxidant solution or antioxidant-rich beverage to regenerate depleted antioxidants on the fiber. Results revealed that the antioxidant capacity of compounds chemically bound to the insoluble moiety could be reconstituted in the presence of other hydrogen-donating substances in the liquid phase. Regeneration efficiency was found to range between 21.5 and 154.3% depending on the type of insoluble food matrix and regeneration agent. Among the food matrices studied, cereal products were found to have slightly higher regeneration efficiency, whereas antioxidant-rich beverages were more effective than pure antioxidants as regeneration agents. Taking wheat bran as reference insoluble material, the regeneration abilities of beverages were in the following order: green tea > espresso coffee > black tea > instant coffee > orange juice > red wine. These results highlighted the possible physiological relevance of antioxidants bound to the insoluble food material in the gastrointestinal tract. During the digestion process they could react with the free radicals and at the same time they can be regenerated by other soluble antioxidant compounds present in the meal
    In vitro callus-induction in globe artichoke (Cynara cardunculus L. var. scolymus) as a system for the production of caffeoylquinic acids
    Menin, B. ; Moglia, A. ; Comino, C. ; Hakkert, J.C. ; Lanteri, S. ; Beekwilder, M.J. - \ 2013
    Journal of Horticultural Science and Biotechnology 88 (2013)5. - ISSN 1462-0316 - p. 537 - 542.
    phenolic-compounds - plant-regeneration - dicaffeoylquinic acids - somatic embryogenesis - growth-regulators - shoot apices - explant type - culture - identification - organogenesis
    Globe artichoke (Cynara cardunculus L. var. scolymus) provides a rich dietary source of bio-active compounds derived from phenylpropanoid metabolism, notably caffeoylquinic acids (CQAs) and flavonoids. Micropropagation techniques have been established for this species, but in vitro cultures have not yet been extended to generate an efficient system for the induction of callus tissue. In this study, we compared more than 100 combinations of media supplements (e.g., phytohormones, absorbers of polyphenols, and inhibitors of polyphenol oxidase), along with various light regimes, and three different genotypes of globe artichoke to define the optimal conditions for callus induction from leaf explants. This led to the elaboration of an in vitro culture protocol which resulted in a high frequency of callus induction after just 1 week in culture. The procedure used leaf explants from virus-free, meristem culture-derived plantlets. Quantitative HPLC analysis revealed that, as in globe artichoke leaves, the predominant phenolic esters present in callus were mono- and di-caffeoylquinic acids (diCQA). The concentration of diCQA was three- to five-fold higher in calli than in leaves. The exposure of calli to UV-C light further enhanced the levels of CQAs. In vitro callus culture combined with UV-C irradiation may thus represent a viable production system for diCQA that is suitable for the synthesis of pharmacologically-active compounds.
    Changes in sour cherry (Prunus cerasus L.) antioxidants during nectar processing and in vitro gastrointestinal digestion.
    Toydemir, G. ; Capanoglu, E. ; Kamiloglu, S. ; Boyacioglu, D. ; Vos, C.H. de; Hall, R.D. ; Beekwilder, M.J. - \ 2013
    Journal of Functional Foods 5 (2013)3. - ISSN 1756-4646 - p. 1402 - 1413.
    phenolic-compounds - vitamin-c - anthocyanins - extract - tomato - degradation - metabolome - capacities - cultivars - stability
    Sour cherry (Prunus cerasus L.) is rich in polyphenols, and like its processed products, is especially rich in anthocyanins. We have applied HPLC, spectrophotometric and on-line antioxidant detection methods to follow the fate of cherry antioxidants during an entire multi-step industrial-scale processing strategy. This was performed for 22 sampling points, with five independent repeats from a commercial cherry nectar production process. Anthocyanins contributed to >50% of the total antioxidant capacity of the samples. An in vitro gastrointestinal (GI) digestion system was used to investigate serum availability of antioxidants. In this system anthocyanin bioavailability was much higher in the processed nectar than in the fresh fruit. Together these results indicate that processed sour cherry nectar is a rich source of stable antioxidants with high bioavailability, auguring well for the potential health-promoting capacity of sour cherry products.
    Emulsifying Property and Antioxidative Activity of Cuttlefish Skin Gelatin Modified with Oxidized Linoleic Acid and Oxidized Tannic Acid
    Aewsiri, T. ; Benjakul, S. ; Visessanguan, W. ; Wierenga, P.A. ; Gruppen, H. - \ 2013
    Food Bioprocess Technology 6 (2013)4. - ISSN 1935-5130 - p. 870 - 881.
    phenolic-compounds - proteins - emulsions - stability - oxidation - charge
    Cuttlefish skin gelatins modified with oxidized linoleic acid (OLA) and oxidized tannic acid (OTA) were characterized and determined for emulsifying properties and antioxidative activity. Modification of gelatin with 5% OTA increased the total phenolic content and 1,1-diphenyl-2-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity and ferric reducing antioxidant power of gelatin–OTA. Incorporation of OLA into gelatin (OLA-to-free amino group molar ratio of 10:1) increased surface hydrophobicity of gelatin from 17.39 to 32.38 and reduce surface tension at air/water interface of gelatin solution from 53 to 32 mN/m. Gelatin–OLA had the increase in emulsion activity index, compared with gelatin without modification and was capable of producing a fine emulsion (d32¿=¿0.79 µm, d43¿=¿0.82 µm). Modification of gelatin–OLA complex with OTA at different concentrations (2.5%, 5%, and 10%) increased antioxidative activity but decrease emulsifying properties. However, gelatin–OLA modified with 5% OTA had higher emulsifying properties than the commercial gelatin (bovine gelatin). The presence of an alkyl group and a hydroxyl group in gelatin after modification with OLA and OTA, respectively, was revealed by Fourier transform infrared study. Coincidental decrease in free amino group was also noticeable in modified gelatin. Menhaden oil-in-water emulsion stabilized by gelatin modified with OLA and 5% OTA was more resistant to lipid oxidation and phase separation as evidenced by the lower thiobarbituric acid reactive substances value and smaller oil droplet size, compared with that stabilized by commercial bovine gelatin. Thus, the modification of gelatin by both OLA and OTA was able to improve antioxidative and emulsifying properties of cuttlefish skin gelatin.
    Changes in polyphenol content during production of grape juice concentrate
    Capanoglu, E. ; Vos, R.C.H. de; Hall, R.D. ; Boyacioglu, D. ; Beekwilder, M.J. - \ 2013
    Food Chemistry 139 (2013)1-4. - ISSN 0308-8146 - p. 521 - 526.
    antioxidant activity - phenolic-compounds - wine - storage - anthocyanins - acid - extraction - quality
    The production of grape juice concentrate on an industrial scale was evaluated and samples from the main steps of processing have been collected and analyzed. The sampling steps included the selection and washing of grapes (Nevsehir Patlak variety), pressing in order to obtain the juice separate from the seed and the skin fraction, pasteurization, clarification, filtration, evaporation, and filling-packing at 27 °C with a Brix of 45°. Samples from each of the processing steps were analyzed by a number of spectrophotometric analyses. A series of anthocyanin compounds was identified using HPLC-MS, and the fate of anthocyanins, quercetin rutinoside and procyanidins was followed using HPLC. The results indicate that the removal of seed and fruit skin removes most of the procyanidins and anthocyanins, while subsequent clarification and filtration treatments further reduce the anthocyanin content.
    Differences in acidity of apples are probably mainly caused by a malic acid transporter gene on LG16
    Khan, S.A. ; Beekwilder, J. ; Schaart, J.G. ; Mumm, R. ; Soriano, J.M. ; Jacobsen, E. ; Schouten, H.J. - \ 2013
    Tree Genetics and Genomes 9 (2013)2. - ISSN 1614-2942 - p. 475 - 487.
    malus-pumila mill. - phenolic-compounds - aluminum tolerance - malate transporter - organic-acids - amino-acids - arabidopsis - metabolism - fruits - inheritance
    Acidity has profound effects on the taste of apples (Malus × domestica). Malic acid is the predominant organic acid in apples. Differences in malic acid content are caused by differences in accumulation of malic acid in the vacuole. This accumulation may be caused by a gene that is responsible for transport of malic acid from the cytosol into the vacuole. Here, we provide evidence that a malic acid transporter gene at the top of chromosome 16 caused significant differences in malic acid concentration and pH of apples. The pH of apples in a segregating F1 population was mapped and at the pH locus (named henceforth Ma locus for malic acid), two putative malic acid transporter genes were detected. These genes show high homology to AtALMT genes that code for malate channel proteins located in vacuolar membrane in Arabidopsis. The expression of one of the candidate genes (Ma1) cosegregated clearly with malic acid content. The inheritance of at least one dominant allele of this gene sufficed for an increased expression level that likely caused the observed threefold increase of the malic acid concentration and the reduction of the pH from 4 to 3 in mature apples, compared to the presence of the recessive, lowly expressed allele only. Our results show that differences in fruit acidity were probably caused by differences in expression levels of alleles of a malic acid transporter gene.
    Application of an untargeted metabolomics approach for the identification of compounds that may be responsible for observed differential effects in chickens fed an organic and a conventional diet
    Ruiz-Aracama, A. ; Lommen, A. ; Huber, M. ; Vijver, L. van de; Hoogenboom, L.A.P. - \ 2012
    Food Additives & Contaminants. Pt. A, Chemistry, Analysis, Control, Exposure & Risk Assessment 29 (2012)3. - ISSN 1944-0049 - p. 323 - 332.
    liquid-chromatography - phenolic-compounds - mass-spectrometry - farming system - food safety - antioxidant - health - corn - biosynthesis - metabolism
    The aim of this study was to apply an untargeted NMR and LC-MS-based metabolomics approach to detect potential differences between an organically and a conventionally produced feed, which caused statistically significant differences in growth, in the response to an immunological challenge and in the gene expression profiles in the small intestine of laying hens. A fractionation procedure was set up to create multiple fractions of the feed, which were subsequently analysed by NMR and UPLC-TOF/MS operating in positive mode. Comparison of the profiles revealed that the most apparent differences came from the isoflavones in the soy as well as a compound with a molecular mass of 441.202 (M¿+¿1)+, which was identified as N,N'-diferuloylputrescine (DFP) and came from the corn. Whether the observed differences in effects are due to the higher levels of isoflavones and DFP is unclear, as is the fact whether the observed differences are typical for organic or conventional produced corn and soy. However, this study shows that this metabolomics approach is suitable for detecting potential differences between products, even in levels of compounds that would have been overlooked with a more targeted approach. As such, the method is suitable for a more systematic study on differences between conventionally and organically produced food. View full textDownload full text
    Impact of Short-Term Intake of Red Wine and Grape Polyphenol Extract on the Human Metabolome
    Jacobs, D.M. ; Fuhrmann, J.C. ; Dorsten, F.A. van; Rein, D. ; Peters, S. ; Velzen, E.J.J. van; Hollebrands, B. ; Draijer, R. ; Duynhoven, J.P.M. van; Garczarek, U. - \ 2012
    Journal of Agricultural and Food Chemistry 60 (2012)12. - ISSN 0021-8561 - p. 3078 - 3085.
    black tea - phenolic-compounds - health - gut - microbiota - biomarkers - urine - acid - microflora - modulation
    Red wine and grape polyphenols are considered to promote cardiovascular health and are involved in multiple biological functions. Their overall impact on the human metabolome is not known. Therefore, exogenous and endogenous metabolic effects were determined in fasting plasma and 24 h urine from healthy male adults consuming a mix of red wine and grape juice extracts (WGM) for 4 days in a placebo-controlled, crossover study. Syringic acid, 3-hydroxyhippuric acid, pyrogallol, 3-hydroxyphenylacetic acid, and 3-hydroxyphenylpropionic acid were confirmed as the strongest urinary markers of WGM intake. Overall, WGM had a mild impact on the endogenous metabolism. Most noticeable were changes in several amino acids deriving from tyrosine and tryptophan. Reductions in the microbial metabolites p-cresol sulfate and 3-indoxylsulfuric acid and increases in indole-3-lactic acid and nicotinic acid were observed in urine. In plasma, tyrosine was reduced. The results suggest that short-term intake of WGM altered microbial protein fermentation and/or amino acid metabolism.
    Correlation of Rutin Accumulation with 3-O-Glucosyl Transferase and Phenylalanine Ammonia-lyase Activities During the Ripening of Tomato Fruit
    Capanoglu, E. ; Beekwilder, J. ; Matros, A. ; Boyacioglu, D. ; Hall, R.D. ; Mock, H.P. - \ 2012
    Plant Foods for Human Nutrition 67 (2012)4. - ISSN 0921-9668 - p. 371 - 376.
    phenolic-compounds - grape berries - plants - expression - resistance - anthocyanins - antioxidant - metabolites - esculentum - induction
    In tomato, the predominant flavonoid is quercetin-3-rutinoside (rutin). In this study, we aim to investigate the phenylalanine ammonia-lyase (PAL) and the quercetin-3-O-glucosyl transferase (3-GT) reactions in the formation of rutin during tomato fruit ripening. Tomatoes of the Moneymaker variety at different development stages (green, breaker, turning, pink, red, and deep red) were divided into flesh and peel fractions. In each sample, both the content of rutin and the enzymatic activities for PAL and 3-GT were recorded. The highest activities of PAL were recorded in the peel of turning fruit (3,000 µkat/mg fresh weight). In fruit flesh, maximal activity was observed in red fruit (917.3 µkat/mg). For both tissues, PAL activity strongly decreased at the final (deep red) fruit stage. The activity of 3-GT in peel peaked in the turning fruit stage (50.7 pkat/mg), while in flesh maximal activity (33.4 pkat/mg) was observed in green fruit, which rapidly declined at the turning stage. Higher levels of rutin were detected in the tomato peel compared to the flesh part with the highest level being found at the green stage. The relation of PAL and 3-GT activities to rutin content is also evaluated.
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