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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    Melanoidins from Coffee, Cocoa, and Bread Are Able to Scavenge α-Dicarbonyl Compounds under Simulated Physiological Conditions
    Zhang, Hao ; Zhang, Hui ; Troise, Antonio Dario ; Fogliano, Vincenzo - \ 2019
    Journal of Agricultural and Food Chemistry 67 (2019)39. - ISSN 0021-8561 - p. 10921 - 10929.
    coffee - dicarbonyls - Maillard reaction - melanoidins - polyphenols

    Free amino residues react with α-dicarbonyl compounds (DCs) contributing to the formation of advanced glycation end products (AGEs). Phenolic compounds can scavenge DCs, thus controlling the dietary carbonyl load. This study showed that high-molecular weight cocoa melanoidins (HMW-COM), HMW bread melanoidins (HMW-BM), and especially HMW coffee melanoidins (HMW-CM) are effective DC scavengers. HMW-CM (1 mg/mL) scavenged more than 40% DCs within 2 h under simulated physiological conditions, suggesting some physiological relevance. Partial acid hydrolysis of HMW-CM decreased the dicarbonyl trapping capacity, demonstrating that the ability to react with glyoxal, methylglyoxal (MGO), and diacetyl was mainly because of polyphenols bound to macromolecules. Caffeic acid (CA) and 3-caffeoylquinic acid showed a DC-scavenging kinetic profile similar to that of HMW-CM, while mass spectrometry data confirmed that hydroxyalkylation and aromatic substitution reactions led to the formation of a stable adduct between CA and MGO. These findings corroborated the idea that antioxidant-rich indigestible materials could limit carbonyl stress and AGE formation across the gastrointestinal tract.

    A Review on the Effect of Drying on Antioxidant Potential of Fruits and Vegetables
    Kamiloglu, Senem ; Toydemir, Gamze ; Boyacioglu, Dilek ; Beekwilder, Jules ; Hall, Robert D. ; Capanoglu, Esra - \ 2016
    Critical Reviews in Food Science and Nutrition 56 (2016). - ISSN 1040-8398 - p. S110 - S129.
    antioxidants - ascorbic acid - carotenoids - Drying - fruits - polyphenols - vegetables

    The role of antioxidants in human nutrition has gained increased interest, especially due to their associated health beneficial effects for a number of chronic diseases, including cardiovascular diseases and certain types of cancer. Fruits and vegetables are perishable and difficult to preserve as fresh products. Dried fruits and vegetables can be easily stored, transported at relatively low cost, have reduced packing costs, and their low water content delays microbial spoilage. Air-, freeze-, microwave- and sun-drying are among the most thoroughly studied drying methods. This review provides an overview of recent findings on the effects of different drying techniques on major antioxidants of fruits and vegetables. In particular, changes in ascorbic acid, carotenoids, flavonoids, phenolic acids, total phenolics, and antioxidant activity are discussed in detail.

    Direct comparison of metabolic health effects of the flavonoids quercetin, hesperetin, epicatechin, apigenin and anthocyanins in high-fat-diet-fed mice
    Hoek-van den Hil, E.F. ; Schothorst, E.M. van; Stelt, I. van der; Swarts, J.J.M. ; Vliet, M.A. van; Amolo, T. ; Vervoort, J.J.M. ; Venema, D.P. ; Hollman, P.C.H. ; Rietjens, I.M.C.M. ; Keijer, J. - \ 2015
    Genes & Nutrition 10 (2015)4. - ISSN 1555-8932 - 13 p.
    cardiovascular-disease - mediterranean diet - c57bl/6j mice - obese mice - bioavailability - polyphenols - inflammation - metaanalysis - cholesterol - prevention
    Dietary flavonoid intake is associated with reduced risk of cardiovascular diseases, possibly by affecting metabolic health. The relative potency of different flavonoids in causing beneficial effects on energy and lipid metabolism has not been investigated. Effects of quercetin, hesperetin, epicatechin, apigenin and anthocyanins in mice fed a high-fat diet (HF) for 12 weeks were compared, relative to normal-fat diet. HF-induced body weight gain was significantly lowered by all flavonoids (17–29 %), but most by quercetin. Quercetin significantly lowered HF-induced hepatic lipid accumulation (71 %). Mesenteric adipose tissue weight and serum leptin levels were significantly lowered by quercetin, hesperetin and anthocyanins. Adipocyte cell size and adipose tissue inflammation were not affected. The effect on body weight and composition could not be explained by individual significant effects on energy intake, energy expenditure or activity. Lipid metabolism was not changed as measured by indirect calorimetry or expression of known lipid metabolic genes in liver and white adipose tissue. Hepatic expression of Cyp2b9 was strongly downregulated by all flavonoids. In conclusion, all flavonoids lowered parameters of HF-induced adiposity, with quercetin being most effective.
    Quercetin tests negative for genotoxicity in transcriptome analyses of liver and small intestine of mice
    Hil, E.F. van den; Schothorst, E.M. van; Stelt, I. van der; Keijer, J. ; Rietjens, I. - \ 2015
    Food and Chemical Toxicology 81 (2015). - ISSN 0278-6915 - p. 34 - 39.
    in-vivo - reverse mutation - bone-marrow - dna-damage - flavonoids - rats - cells - carcinogenicity - mutagenicity - polyphenols
    Given the positive results of quercetin in in vitro genotoxicity studies, the in vivo genotoxic properties of this important dietary flavonoid warrant testing, especially considering possible high intake via widely available food supplements. Here, this was done by transcriptome analyses of the most relevant tissues, liver and small intestine, of quercetin supplemented mice. Quercetin (0.33%) supplemented to a high-fat diet was administered to mice during 12 weeks. Serum alanine aminotransferase and aspartate aminotransferase levels revealed no indications for hepatotoxicity. Microarray pathway analysis of liver and small intestine showed no regulation of genotoxicity related pathways. Analysis of DNA damage related genes also did not point at genotoxicity. Furthermore, a published classifier set of transcripts for identifying genotoxic compounds did not indicate genotoxicity. Only two transcripts of the classifier set were regulated, but in the opposite direction compared with the genotoxic compounds 2-acetylaminofluorene (2-AAF) and aflatoxin B1 (AFB1). Based on the weight of evidence of three different types of analysis, we conclude that supplementation with quercetin at ~350¿mg/kg bw/day for 12 weeks in mice showed no up-regulation of genotoxicity related pathways in liver and small intestine.
    Combining an in vitro reporter gene assay with metabolomics to identify tomato phytochemicals responsible for inducing electrophile-responsive element (EpRE)-mediated gene transcription
    Eekelen, H.D.L.M. van; Gijsbers, L. ; Maliepaard, C.A. ; Vreeburg, R.A.M. ; Finkers, H.J. ; Tikunov, Y.M. ; Gomez Roldan, M.V. ; Haan, L.H.J. de; Vos, R.C.H. de; Aarts, J.M.M.J.G. ; Rietjens, I. ; Bovy, A.G. - \ 2015
    Metabolomics 11 (2015)2. - ISSN 1573-3882 - p. 302 - 311.
    solanum-lycopersicon - mass-spectrometry - fruit - expression - health - metabolism - flavonoids - lycopene - deglycosylation - polyphenols
    The electrophile-responsive element (EpRE) is a transcriptional enhancer involved in cancer-chemoprotective gene expression effects of certain dietary compounds. In this study we measured the ability of extracts of glycosidase treated tomato fruits from 97 different accessions to induce EpRE-mediated luciferase expression using EpRE-LUX reporter cells and analyzed the same extracts using LC–MSbased untargeted metabolomics profiling. We were able to pinpoint those tomato compounds that were most correlated with EpRE-mediated luciferase induction, by combining reporter gene assay data with the metabolic profiles of the same extracts. Flavonoids were the compounds showing the strongest positive correlation with EpRE-LUX activity. These results were validated using a transgenic tomato line accumulating high levels of flavonoids. Results obtained corroborated that flavonoids are an important determinant of the ability of tomato fruit extracts to induce EpRE-mediated beneficial health effects. Overall, these results indicate that combining untargeted metabolomics with reporter gene assays provides a powerful tool for nutritionists, plant breeders and food chemists towards identification of potential health-beneficial constituents of tomato fruits, as well as of other crops and products derived thereof.
    Mechanism of Isoflavone Adsorption from Okara extracts onto Food-Grade Resins
    Méndez Sevillano, D. ; Jankowiak, L. ; Gaalen, T.L.T. van; Wielen, L.A.M. van der; Hooshyar, N. ; Goot, A.J. van der; Ottens, M. - \ 2014
    Industrial & Engineering Chemistry Research 53 (2014)39. - ISSN 0888-5885 - p. 15245 - 15252.
    defatted soybean flakes - dietary fiber - by-product - soy milk - polyphenols - selection - caffeine - binding
    Okara is a byproduct of the soy milk industry containing valuable phytochemicals, called isoflavones, among other components (i.e., proteins, sugars, fibers, etc.). As a waste product, okara is an interesting source material for obtaining valuable chemicals, and knowledge of the behavior of such components in their complex matrix is a key step for design of a purification process. Six commercially available macroporous polymeric resins are investigated to measure and model the equilibrium properties of the adsorption of isoflavones, proteins, and total solids onto these resins. A new model is evaluated in which adsorption of isoflavones onto a protein layer is proposed describing the system isoflavones–resin XAD 4 better than a linear isotherm model. Parameters for both the linear model and the bilayer model are regressed and reported with their accuracy and correlated to the hydrophobicity of each of the isoflavones.
    Coffee and tea consumption, genotype-based CYP1A2 and NAT2 activity and colorectal cancer risk—Results from the EPIC cohort study
    Dik, V.K. ; Bueno-de-Mesquita, H.B. ; Oijen, M.G.C.T. van; Siersema, P.D. ; Uiterwaal, C.S.P.M. ; Gils, C.H. van; Duijnhoven, F.J.B. van - \ 2014
    International Journal of Cancer 135 (2014)2. - ISSN 0020-7136 - p. 401 - 412.
    colonic aberrant crypts - green tea - components kahweol - black tea - caffeine - cafestol - polyphenols - health - cells - rat
    Coffee and tea contain numerous antimutagenic and antioxidant components and high levels of caffeine that may protect against colorectal cancer (CRC). We investigated the association between coffee and tea consumption and CRC risk and studied potential effect modification by CYP1A2 and NAT2 genotypes, enzymes involved in the metabolization of caffeine. Data from 477,071 participants (70.2% female) of the European Investigation into Cancer and Nutrition (EPIC) cohort study were analyzed. At baseline (1992–2000) habitual (total, caffeinated and decaffeinated) coffee and tea consumption was assessed with dietary questionnaires. Cox proportional hazards models were used to estimate adjusted hazard ratio's (HR) and 95% confidence intervals (95% CI). Potential effect modification by genotype-based CYP1A2 and NAT2 activity was studied in a nested case–control set of 1,252 cases and 2,175 controls. After a median follow-up of 11.6 years, 4,234 participants developed CRC (mean age 64.7¿±¿8.3 years). Total coffee consumption (high vs. non/low) was not associated with CRC risk (HR 1.06, 95% CI 0.95–1.18) or subsite cancers, and no significant associations were found for caffeinated (HR 1.10, 95% CI 0.97–1.26) and decaffeinated coffee (HR 0.96, 95% CI 0.84–1.11) and tea (HR 0.97, 95% CI 0.86–1.09). High coffee and tea consuming subjects with slow CYP1A2 or NAT2 activity had a similar CRC risk compared to non/low coffee and tea consuming subjects with a fast CYP1A2 or NAT2 activity, which suggests that caffeine metabolism does not affect the link between coffee and tea consumption and CRC risk. This study shows that coffee and tea consumption is not likely to be associated with overall CRC.
    Analytical Strategy Coupled with Response Surface Methodology To Maximize the Extraction of Antioxidants from Ternary Mixtures of Green, Yellow, and Red Teas (Camillia sinensis var. Sinensis)
    Granato, D. ; Grevink, R. ; Zielinski, R. ; Nunes, D.S. ; Ruth, S.M. van - \ 2014
    Journal of Agricultural and Food Chemistry 62 (2014)42. - ISSN 0021-8561 - p. 10283 - 10296.
    ilex-paraguariensis - optimization - capacity - white - assay - polyphenols - catechins
    This work aimed at using a simplex-centroid design to model the effects of green, yellow, and red tea mixtures (Camellia sinensis var. sinensis) on metal chelation activity, phenolic composition, antioxidant activity, and instrumental taste profile. The regression models that described the extraction of flavan-3-ols, o-diphenols, total phenolic compounds (TPC), free radical scavenging activity toward 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), cupric ion reducing antioxidant activity (CUPRAC), and ferric reducing antioxidant power (FRAP) were significant, and data were fit satisfactorily (R2 > 80%). A mixture of green and red teas had a synergism in CUPRAC and TPC, whereas a mixture of yellow and red teas had a positive effect on CUPRAC and DPPH. An optimization was performed to maximize the antioxidant activity and flavan-3-ol content and to render a tea with mild bitterness, and results showed that a mixture of 14.81% green, 56.86% yellow, and 28.33% red teas would be the most suitable combination of factors.
    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.
    Direct estimate of cocoa powder content in cakes by colorimetry and photoacoustic spectroscopy
    Doka, O. ; Bicanic, D.D. ; Kulcsar, R. - \ 2014
    International Journal of Thermophysics 35 (2014)12. - ISSN 0195-928X - p. 2206 - 2214.
    phenolic content - theobroma-cacao - antioxidant - quantification - polyphenols - chocolate - capacity - beans - fat
    Cocoa is a very important ingredient in the food industry and largely consumed worldwide. In this investigation, colorimetry and photoacoustic spectroscopy were used to directly assess the content of cocoa powder in cakes; both methods provided satisfactory results. The calibration curve was constructed using a series of home-made cakes containing varying amount of cocoa powder. Then, at a later stage, the same calibration curve was used to quantify the cocoa content of several commercially available cakes. For self-made cakes, the relationship between the PAS signal and the content of cocoa powder was linear while a quadratic dependence was obtained for the colorimetric index TeX (brightness) and total color difference
    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.
    Dietary intakes of individual flavanols and flavonols are inversely associated with incident type 2 diabetes in European populations
    Zamora-Ros, R. ; Forouhi, N.G. ; Sharp, S.J. ; Gonzalez, C.A. ; Buijsse, B. ; Schouw, Y.T. van der; Boeing, H. ; Feskens, E.J.M. ; Woudenbergh, G.J. van - \ 2014
    The Journal of Nutrition 144 (2014)3. - ISSN 0022-3166 - p. 335 - 343.
    epic-interact - food sources - nutrition - cancer - polyphenols - risk - women - humans - cohort - tea
    Dietary flavanols and flavonols, flavonoid subclasses, have been recently associated with a lower risk of type 2 diabetes (T2D) in Europe. Even within the same subclass, flavonoids may differ considerably in bioavailability and bioactivity. We aimed to examine the association between individual flavanol and flavonol intakes and risk of developing T2D across European countries. The European Prospective Investigation into Cancer and Nutrition (EPIC)–InterAct case-cohort study was conducted in 8 European countries across 26 study centers with 340,234 participants contributing 3.99 million person-years of follow-up, among whom 12,403 incident T2D cases were ascertained and a center-stratified subcohort of 16,154 individuals was defined. We estimated flavonoid intake at baseline from validated dietary questionnaires using a database developed from Phenol-Explorer and USDA databases. We used country-specific Prentice-weighted Cox regression models and random-effects meta-analysis methods to estimate HRs. Among the flavanol subclass, we observed significant inverse trends between intakes of all individual flavan-3-ol monomers and risk of T2D in multivariable models (all P-trend <0.05). We also observed significant trends for the intakes of proanthocyanidin dimers (HR for the highest vs. the lowest quintile: 0.81; 95% CI: 0.71, 0.92; P-trend = 0.003) and trimers (HR: 0.91; 95% CI: 0.80, 1.04; P-trend = 0.07) but not for proanthocyanidins with a greater polymerization degree. Among the flavonol subclass, myricetin (HR: 0.77; 95% CI: 0.64, 0.93; P-trend = 0.001) was associated with a lower incidence of T2D. This large and heterogeneous European study showed inverse associations between all individual flavan-3-ol monomers, proanthocyanidins with a low polymerization degree, and the flavonol myricetin and incident T2D. These results suggest that individual flavonoids have different roles in the etiology of T2D
    Interaction of flavan-3-ol derivatives and different caseins is determined by more than proline content and number of proline repeats
    Bohin, M.C. ; Vincken, J.P. ; Westphal, A.H. ; Tripp, A.M. ; Dekker, Peter ; Hijden, H.T.W.M. ; Gruppen, H. - \ 2014
    Food Chemistry 158 (2014). - ISSN 0308-8146 - p. 408 - 416.
    food proteins - binding - astringency - polymerization - precipitation - complexation - fluorescence - procyanidins - polyphenols - gallate
    Interactions of Type A and B flavan-3-ol dimers (procyanidins) and several monomeric flavan-3-ols, with a-casein and ß-casein, were investigated. Binding affinities measured were related to the ligands structure, including several properties (e.g. intrinsic flexibility (number of rotatable bonds) and hydrophobicity), and to the amino-acid composition of the caseins. A monomeric flavan-3-ol esterified with gallic acid (EGCG) had a five to ten times higher affinity to caseins compared to the non-galloylated dimeric flavan-3-ols. In this case, the larger number of rotatable bonds in EGCG might be accountable for this difference. Comparing flavan-3-ol dimers, intrinsic flexibility did not consistently promote interactions, as procyanidin A1 displayed a higher affinity to a-casein than the supposedly more flexible B-type dimers investigated. Despite its higher content of proline, compared to a-casein, ß-casein did not always have a higher affinity for the ligands investigated (e.g. no interaction with procyanidin A1 detected). These results suggest that more factors than proline content and the number of proline repeats govern phenolic–casein interactions.
    Effects of chocolate supplementation on metabolic and cardiovascular parameters in ApoE3L mice fed a high-cholesterol atherogenic diet
    Yakala, G.K. ; Wielinga, P.Y. ; Suarez, M. ; Bunschoten, A. ; Golde, J.M. ; Arola, L. ; Keijer, J. ; Kleemann, R. ; Kooistra, T. ; Heeringa, P. - \ 2013
    Molecular Nutrition & Food Research 57 (2013)11. - ISSN 1613-4125 - p. 2039 - 2048.
    e-asterisk-3-leiden transgenic mice - coronary-heart-disease - kusanagi-hypercholesterolemic rabbits - reduce plasma-cholesterol - lipid-peroxidation - life-style - atherosclerosis - health - polyphenols - prevention
    SCOPE: Dietary intake of cocoa and/or chocolate has been suggested to exhibit protective cardiovascular effects although this is still controversial. The aim of this study was to investigate the effects of chocolate supplementation on metabolic and cardiovascular parameters. METHODS AND RESULTS: Four groups of ApoE*3Leiden mice were exposed to the following diet regimens. Group 1: cholesterol-free control diet (CO). Group 2: high-dose (1.0% w/w) control cholesterol (CC). Group 3: CC supplemented chocolate A (CCA) and Group 4: CC supplemented chocolate B (CCB). Both chocolates differed in polyphenol and fiber content, CCA had a relatively high-polyphenol and low-fiber content compared to CCB. Mice fed a high-cholesterol diet showed increased plasma-cholesterol and developed atherosclerosis. Both chocolate treatments, particularly CCA, further increased plasma-cholesterol and increased atherosclerotic plaque formation. Moreover, compared to mice fed a high-cholesterol diet, both chocolate-treated groups displayed increased liver injury. Mice on high-cholesterol diet had elevated plasma levels of sVCAM-1, sE-selectin and SAA, which was further increased in the CCB group. Similar effects were observed for renal inflammation markers. CONCLUSION: The two chocolate preparations showed unfavorable, but different effects on cardiometabolic health in E3L mice, which dissimilarities may be related to differences in chocolate composition. We conclude that discrepancies reported on the effects of chocolate on cardiometabolic health may at least partly be due to differences in chocolate composition.
    The Association between dietary flavonoid and lignan intakes and incident type 2 diabetes in European populations
    Zamora-Ros, R. ; Forouhi, N.G. ; Buijsse, B. ; Schouw, Y.T. van der; Boeing, H. ; Feskens, E.J.M. - \ 2013
    Diabetes Care 36 (2013)12. - ISSN 0149-5992 - p. 3961 - 3970.
    insulin sensitivity - risk-factors - food sources - life-style - us men - nutrition - cancer - women - cohort - polyphenols
    OBJECTIVE To study the association between dietary flavonoid and lignan intakes, and the risk of development of type 2 diabetes among European populations. RESEARCH DESIGN AND METHODS The European Prospective Investigation into Cancer and Nutrition-InterAct case-cohort study included 12,403 incident type 2 diabetes cases and a stratified subcohort of 16,154 participants from among 340,234 participants with 3.99 million person-years of follow-up in eight European countries. At baseline, country-specific validated dietary questionnaires were used. A flavonoid and lignan food composition database was developed from the Phenol-Explorer, the U.K. Food Standards Agency, and the U.S. Department of Agriculture databases. Hazard ratios (HRs) from country-specific Prentice-weighted Cox regression models were pooled using random-effects meta-analysis. RESULTS In multivariable models, a trend for an inverse association between total flavonoid intake and type 2 diabetes was observed (HR for the highest vs. the lowest quintile, 0.90 [95% CI 0.77–1.04]; P value trend = 0.040), but not with lignans (HR 0.88 [95% CI 0.72–1.07]; P value trend = 0.119). Among flavonoid subclasses, flavonols (HR 0.81 [95% CI 0.69–0.95]; P value trend = 0.020) and flavanols (HR 0.82 [95% CI 0.68–0.99]; P value trend = 0.012), including flavan-3-ol monomers (HR 0.73 [95% CI 0.57–0.93]; P value trend = 0.029), were associated with a significantly reduced hazard of diabetes. CONCLUSIONS Prospective findings in this large European cohort demonstrate inverse associations between flavonoids, particularly flavanols and flavonols, and incident type 2 diabetes. This suggests a potential protective role of eating a diet rich in flavonoids, a dietary pattern based on plant-based foods, in the prevention of type 2 diabetes
    Automatic Chemical Structure Annotation of an LC-MSn Based Metabolic Profile from Green Tea
    Ridder, L.O. ; Hooft, J.J.J. van der; Verhoeven, S. ; Vos, C.H. de; Bino, R.J. ; Vervoort, J. - \ 2013
    Analytical Chemistry 85 (2013)12. - ISSN 0003-2700 - p. 6033 - 6040.
    accurate mass-spectrometry - camelia-sinensis extracts - spectral trees - oolong tea - identification - fragmentation - elucidation - flavan-3-ols - polyphenols - software
    Liquid chromatography coupled with multistage accurate mass spectrometry (LC–MSn) can generate comprehensive spectral information of metabolites in crude extracts. To support structural characterization of the many metabolites present in such complex samples, we present a novel method (http://www.emetabolomics.org/magma) to automatically process and annotate the LC–MSn data sets on the basis of candidate molecules from chemical databases, such as PubChem or the Human Metabolite Database. Multistage MSn spectral data is automatically annotated with hierarchical trees of in silico generated substructures of candidate molecules to explain the observed fragment ions and alternative candidates are ranked on the basis of the calculated matching score. We tested this method on an untargeted LC–MSn (n = 3) data set of a green tea extract, generated on an LC-LTQ/Orbitrap hybrid MS system. For the 623 spectral trees obtained in a single LC–MSn run, a total of 116¿240 candidate molecules with monoisotopic masses matching within 5 ppm mass accuracy were retrieved from the PubChem database, ranging from 4 to 1327 candidates per molecular ion. The matching scores were used to rank the candidate molecules for each LC–MSn component. The median and third quartile fractional ranks for 85 previously identified tea compounds were 3.5 and 7.5, respectively. The substructure annotations and rankings provided detailed structural information of the detected components, beyond annotation with elemental formula only. Twenty-four additional components were putatively identified by expert interpretation of the automatically annotated data set, illustrating the potential to support systematic and untargeted metabolite identification.
    Colorimetry and photoacoustic spectroscopy as suitable tools for direct determination of cocoa powder in confectionary products
    Doka, O. ; Pragai, E. ; Bicanic, D.D. ; Kulcsar, R. - \ 2013
    European Food Research and Technology 236 (2013)6. - ISSN 1438-2377 - p. 963 - 968.
    phenolic content - theobroma-cacao - powders - antioxidant - quantification - polyphenols - mixtures - capacity - samples - beans
    Laser photoacoustic spectroscopy (PAS) and colorimetry have been used to rapidly and accurately determine the content of fat-free cocoa solids in dark chocolates. Both techniques are inexpensive and require only a one-time calibration step versus a method capable of absolute concentration measurement (for example HPLC). Once the response of PAS and/or colorimetry has been obtained, the content of fat-free cocoa solids in dark chocolates can be determined directly (i.e. without any sample preparation including the process of extraction) from the calibration curves and the experimentally measured microphone signal (in PAS studies) and colorimetric indices L* and ¿E* (in colorimetric investigations). Both colorimetric indices and PA signals correlate positively with the content of fat-free cocoa solids. The correlation is highly linear over a wide concentration range (25–50 %).
    SPE-NMR metabolite sub-profiling of urine
    Jacobs, D.M. ; Spiesser, L. ; Garnier, M. ; Roo, N. de; Dorsten, F. van; Hollebrands, B. ; Velzen, E. van; Draijer, R. ; Duynhoven, J.P.M. van - \ 2012
    Analytical and Bioanalytical Chemistry 404 (2012)8. - ISSN 1618-2642 - p. 2349 - 2361.
    red wine - nutrition research - metabolomics - polyphenols - gut - humans - health - impact - milk - identification
    NMR-based metabolite profiling of urine is a fast and reproducible method for detection of numerous metabolites with diverse chemical properties. However, signal overlap in the (1)H NMR profiles of human urine may hamper quantification and identification of metabolites. Therefore, a new method has been developed using automated solid-phase extraction (SPE) combined with NMR metabolite profiling. SPE-NMR of urine resulted in three fractions with complementary and reproducible sub-profiles. The sub-profile from the wash fraction (100 % water) contained polar metabolites; that from the first eluted fraction (10 % methanol-90 % water) semi-polar metabolites; and that from the second eluted fraction (100 % methanol) aromatic metabolites. The method was validated by analysis of urine samples collected from a crossover human nutritional intervention trial in which healthy volunteers consumed capsules containing a polyphenol-rich mixture of red wine and grape juice extract (WGM), the same polyphenol mixture dissolved in a soy drink (WGM_Soy), or a placebo (PLA), over a period of five days. Consumption of WGM clearly increased urinary excretion of 4-hydroxyhippuric acid, hippuric acid, 3-hydroxyphenylacetic acid, homovanillic acid, and 3-(3-hydroxyphenyl)-3-hydroxypropionic acid. However, there was no difference between the excreted amounts of these metabolites after consumption of WGM or WGM_Soy, indicating that the soy drink is a suitable carrier for WGM polyphenols. Interestingly, WGM_Soy induced a significant increase in excretion of cis-aconitate compared with WGM and PLA, suggesting a higher demand on the tricarboxylic acid cycle. In conclusion, SPE-NMR metabolite sub-profiling is a reliable and improved method for quantification and identification of metabolites in urine to discover dietary effects and markers of phytochemical exposure
    Proctection by Flavonal-Rich foods against vascular dysfunction and oxidative damage: 27th Hohenheim consensus conference
    Sies, H. ; Hollman, P.C.H. ; Grune, T. ; Stahl, W. - \ 2012
    Advances in Nutrition 3 (2012). - ISSN 2161-8313 - p. 217 - 221.
    antioxidant capacity assays - arterial stiffness - protein oxidation - dietary-intake - health claims - comet assay - polyphenols - disease - flavonoids - consumption
    Criteria for assessing the purported protection by flavanol-rich foods against vascular dysfunction and oxidative damage to biomolecules was the subject of the 27th Hohenheim Consensus Conference held on July 11, 2011. State-of-the-art evidence was put into perspective, focusing on several questions that were followed by a consensus answer. Among the topics addressed were the major sources of flavanols in the human diet, the bioavailability of flavanols, biomarkers for “health benefit,” and the biological function of flavanols. Consensus was reached on these topics. No conclusion was reached on the design of randomized, controlled trials for substantiation of health claims for flavanol-rich foods as to the necessity of a study arm with an isolated pharmacologically active compound, e.g., (-)-epicatechin.
    Amino acid profile of salivary proteins and plasmatic trace mineral response to dietary condensed tannins in free-ranging zebu cattle (Bos indicus) as a marker of habitat degradation
    Yisehak, K. ; Becker, A. ; Rothman, J.M. ; Dierenfeld, E.S. ; Marescau, B. ; Bosch, G. ; Hendriks, W.H. ; Janssens, G.P.J. - \ 2012
    Livestock Science 144 (2012)3. - ISSN 1871-1413 - p. 275 - 280.
    proline-rich proteins - lotus-pedunculatus - dairy-cows - binding - sheep - iron - adaptation - ruminants - antioxidant - polyphenols
    In the southern hemisphere, foraging areas of cattle are affected by overgrazing and soil erosion resulting in decreased availability of grasses and increased amounts of browse plants high in condensed tannins (CT). This study aimed to identify biomarkers in free-ranging zebu cattle (Bos indicus) for the habitat degradation, based on their salivary and trace mineral response to dietary CT. Saliva and blood samples were collected from 60 randomly involved free-ranging zebu bulls in six study sites, which were further grouped into two regions based on the average CT concentration in the plants regularly consumed by the cattle. Jugular venipunctures for blood sampling and the swabbing technique for saliva collection were used. Plasma samples were analyzed for Cu, Zn and Fe. Saliva samples were analyzed for total amino acid concentrations. Average CT concentrations in the plants ranged between 0 and 166 g CT/kg dry matter (P <0.001). Higher CT levels were associated with reduced plasma Cu (P <0.05) whereas Fe was not affected (P > 0.05). In contrast to Cu, higher Zn concentration was found in the region rich in CT content (P <0.05). The proportion of proline of total amino acids, as main indicator of salivary proline-rich proteins in the saliva, was higher in the tannin-rich region (P <0.01). The ratio of proline to the sum of total amino acids was also higher in this region (P <0.001). Higher ratio of salivary arginine to ornithine was observed in the tannin-rich region (P <0.05), suggesting reduced ruminal protein synthesis due to reduced protein bio-availability. In conclusion, the increase in salivary proline concentration in free-ranging zebu cattle reflects the dietary CT load, which in turn suggests habitat degradation and lower availability of feed sources.
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