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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    Empowering breeding programs with new approaches to overcome constraints for selecting superior quality traits of rice
    Calingacion, M.N. - \ 2015
    Wageningen University. Promotor(en): Robert Hall; M.A. Fitzgerald, co-promotor(en): Roland Mumm. - Wageningen : Wageningen University - ISBN 9789462572188 - 198
    oryza sativa - rijst - rassen (planten) - cultivars - genetische diversiteit - gewaskwaliteit - aroma - geur en smaak - consumentenvoorkeuren - plantenveredeling - veredelingsprogramma's - oryza sativa - rice - varieties - cultivars - genetic diversity - crop quality - aroma - flavour - consumer preferences - plant breeding - breeding programmes

    Empowering breeding programs with new approaches to overcome constraints for selecting superior quality traits of rice

    Mariafe N. Calingacion

    Most rice breeding programs have focused on improving agronomic traits such as yield, while enhancing grain quality traits such as flavour and aroma, especially of non-fragrant rices, has not been given high priority. In this study, we utilised a multi-disciplinary approach to understand better quality traits of aroma and flavour in rice grains, and to determine whether good flavour in the grain could be combined with stress tolerant genotypes.

    To understand what factors drive rice preferences, an extensive survey among members of the International Network for Quality Rice who are local experts in grain quality evaluation programs in 25 countries was conducted (Chapter 2). The objective was to identify the grain quality characteristics of the popular rice varieties in each region. Eighteen combinations of size and shape of the grain, amylose content (AC), gelatinisation temperature (GT) and fragrance were identified. These trait combinations reveal the complexity of consumer preferences. The two most popular combinations both have long and slender grains, while one has low amylose, low GT and is aromatic, and the other has intermediate AC and intermediate GT and is non-aromatic. Further evaluation of varieties having the same combination of grain quality traits showed that consumers readily identify differences between these varieties. For example, BRS Primavera and IR64 that are popular in Brazil and in the Philippines, respectively, have the same combination of all 18 traits, however, panellists of sensory evaluation can easily perceive differences in aroma and flavour of BRS Primavera and IR64. This emphasises that the current tools we have available to assess rice quality are unable to capture all the quality traits consumers are looking for in rice.

    In Chapter 3, a novel multiplatform metabolomic and ionomic approach with genome-wide genotyping was utilised to investigate the effect of different nitrogen fertiliser regimes on the biochemical profile of three premium waxy rice varieties, Hom Nang Nouane (HNN), Kai Noi Leuanag (KNL) and Tha Sa No (TSN) from Lao PDR. The current tools used to phenotype grain quality such as GT, values from viscosity curves, and hardness and stickiness, were unable to differentiate between HNN, KNL and TSN either on the basis of nitrogen treatment nor genotype. However, metabolite profiling of metabolites and minerals followed by multivariate statistical methods readily separated the genotypes on each platform, and discriminatory compounds that were identified were relevant to consumers in terms of flavour, taste and nutrition. However, despite yield differences, nitrogen treatment did not significantly affect the overall metabolite and mineral profiles of the samples. Using 1536 single nucleotide polymorphism (SNP) loci, the Euclidean distance between each variety was calculated and compared to the distance between each variety for each metabolomic platform. Procrustes analysis was used to rotate and scale the variety mean scores on the metabolite principal components to give the best fit to the genetic principal coordinates. Comparing the triangles whereby each vertex of the triangle is a variety and the length of each side is equal to the scaled Euclidean distance, mineral elements, polar metabolites and volatile compounds all associate very well with the genetic distance between each variety. This study highlights that multiple metabolomic platforms are potential phenotyping tools to characterise rice quality in a comprehensive and efficient way, and in a way that provides data that is relevant to consumers.

    To gain insights on the influence of water availability to the metabolomic profile of drought tolerant rice, two contrasting varieties, Apo and IR64, and a mapping population derived from them were extensively characterised in Chapters 4 and 5. Apo is drought tolerant but has unacceptable grain quality while IR64 is drought susceptible with premium grain quality. Apo and IR64 were grown under irrigated and drought conditions. Yield of Apo from both water conditions was higher than yield of IR64 under the same conditions. Moreover, metabolite profiling and sensory analysis showed that grains of Apo were not affected by drought conditions i.e. panellists perceived no difference in the aroma of Apo from both conditions and Principal Components Analysis (PCA) of the volatiles showed one cluster of Apo from both conditions. However, grains of IR64 formed two clusters based on water condition in the PCA and panellists were able to perceive ‘water-like metallic’ aroma in IR64 that was grown under drought conditions but this was not detected in grains from the irrigated treatment. This suggests that response to water stress in the metabolomic profile of the grain is variety dependent.

    In Chapter 5, a mapping population derived from Apo and IR64 was grown, with the parents, under irrigated and drought conditions. The yield of more than half of the population was higher than the yield of Apo and IR64 under both irrigated and drought conditions; this indicates significant transgressive segregation. Using a dense linkage map based on genotyping by sequencing data, quantitative trait loci (QTL) analysis of drought stress identified one major QTL on chromosome 3 that is likely to be qDTY3.1 which was previously detected in a population derived from Apo as the drought tolerant parent. All the lines of the population carrying this QTL showed significantly higher yield under drought than those without it, indicating the potential importance of this QTL in drought tolerance.

    Metabolite profiling and sensory analysis were also conducted in the grains of the population. More than a hundred volatiles were detected in the headspace of rice samples and PC1 and PC2 explained 55.6% of the variation in the metabolite profiles with many of the lines clustering in between the Apo and IR64 parent values. Six novel metabolite QTLs for volatile compounds were identified - 1 QTL was detected in chromosome 1 for 3,7-dimethyl-octen-1-ol, 1 QTL for hexanol in chromosome 2, and 4 QTLs for pentanol, hexanol, hexanal, and heptanone in chromosome 3. Interestingly, three lines were observed by the panellists to have similar aroma as IR64 while four lines were observed to have similar aroma as that perceived in Apo. Lines 20, 164 and 28 were perceived by the panellists to have high levels of corn, dairy and sweet aromatic features. Moreover, the yield of these 3 lines under both irrigated and drought conditions was similar to that of the Apo parent under the same conditions with Line 28 yielding the highest under drought and has the QTL associated with yield under drought on chromosome 3.

    Finally, the potential of metabolomics as a phenotyping tool in characterising grain quality is further highlighted in Chapter 6. Combining metabolomics with high throughput genotyping and sensory analysis offers new breadth of approach in understanding grain quality of rice. Three lines identified that carry IR64 quality along with high yield in both irrigation and drought, are recommended to enter a rice breeding program at the stage of advanced replicated and multi-location testing. By using advanced tools of phenotyping and genotyping, with validation by sensory panels, these three advanced lines have been selected in just three years.

    A taste of pepper: genetics, biochemistry and prediction of sweet pepper flavor
    Eggink, P.M. - \ 2013
    Wageningen University. Promotor(en): Richard Visser, co-promotor(en): Arnaud Bovy; Chris Maliepaard; J.P.W. Haanstra. - S.l. : s.n. - ISBN 9789461737243 - 159
    capsicum annuum - paprika's - wilde verwanten - genotypen - chemische samenstelling - smaak - geur en smaak - capsicum baccatum - introgressie - plantenveredeling - capsicum annuum - sweet peppers - wild relatives - genotypes - chemical composition - taste - flavour - capsicum baccatum - introgression - plant breeding

    This PhD project started with the composition of a diverse panel of genotypes that represented, (i) roughly the flavor variation in the commercial Capsicum annuum breeding program of Rijk Zwaan, (ii) parents of available mapping populations and (iii) some genotypes that were expected to have extraordinary flavors. The complete set consisted of 35 genotypes of which 24 genotypes were non-pungent. Volatile and non-volatile compounds as well as some breeding parameters were measured in mature fruits of all genotypes throughout the growing season. In addition, from three harvests the non-pungent genotypes were evaluated for taste by a trained descriptive sensory panel.

    The biochemical profiling with use of SPME-GC-MS allowed visualization of between- and within-species volatile compound variation. Principal components analysis (PCA) on the intensity patterns of 391 putative volatile compounds revealed individual grouping of C. chinense, C. baccatum var. pendulum and C. annuum, indicating potentially interesting volatile variation present in the former two groups. A large group of saturated and unsaturated esters were mainly responsible for the individual grouping of the C. chinense accessions. Due to the elevated acid concentrations and aberrant volatile profiles of the C. baccatum var. pendulum accessions PEN45 and PEN79, the two BIL populations derived from these accessions were identified as interesting candidates for further study. Compared to e.g. Mazurka the citrate concentration of the C. baccatum accessions was 2.5-3 times higher and the malate concentrations were even up to 12 times higher (Chapter 2).

    Based on the non-pungent genotypes, we found highly correlated clusters of volatiles and non-volatiles, which could be related to metabolic pathways and common biochemical precursors (Chapter 3). Contrasts between genotypes were caused by both qualitative and quantitative differences in these metabolic clusters, with the phenolic derivatives, higher alkanes, sesquiterpenes and lipid derived volatiles forming the major determinants. For the description of the non-pungent genotypes the panelists used fourteen attributes to describe the flavor sensation in the mouth/throat, which were the texture attributes crunchiness, stickiness of the skin, toughness and juiciness, the basic taste attributes sweetness and sourness and the retronasal flavor attributes aroma intensity, grassiness, green bean, carrot, fruity/apple, perfume, petrochemical and musty. The variation in flavor could be reduced into two major sensory contrasts, which were a texture related contrast and the basic sweet-sour contrast. The structure of the PCA plots resulting from the analysis with one harvest (Chapter 3) and the analysis with the combined three harvests (Chapter 4) remained almost identical, indicating the stability of these contrasts. To relate the sensory attributes to the metabolite data and to determine the importance of the individual compounds we used Random Forest regression on the individual harvests and on the three harvests together. Several predictors for the attributes aroma, fruity/apple, sourness and sweetness were found in common between harvests, which we proposed as key-metabolites involved in flavor determination of sweet pepper (Chapter 4). This list contains compounds with known relations to attributes, like sweetness and sugars, but also several compounds with new relations. In this respect we have demonstrated for the first time, that the metabolites p-menth-1-en-9-al, (E)-β-ocimene, (Z)-2-penten-1-ol, and 1-methyl-1,4-cyclohexadiene are related to fruity/apple taste and/or sweetness of pepper. For sourness the only compound with a consistent significant contribution was an unknown C6H8O2 compound. We postulated therefore the hypothesis that in pepper the effect of sourness related metabolites is masked by other volatile and non-volatile compounds or texture differences (Chapter 3). Subsequently in Chapter 4 we described a clear sweetness-sourness interaction and demonstrated that the masking effect of fructose and other sugars explained why we did not find organic acids contributing to the prediction of sourness. The major sensory attributes were also predicted between harvests. The Random Forest predictions of the texture related attributes (juiciness, toughness, crunchiness and stickiness of the skin) and sweetness were very good. The predictions of the attributes aroma intensity, sourness and fruity/apple were somewhat lower and more variable between harvests, especially in the second harvest. In general, we concluded that prediction of attributes with higher heritabilities works better and is more consistent over harvests (Chapter 4).

    Based on the results of the initial experiments (Chapter 2) the species C. baccatum was chosen for further study. To exploit the potential flavor wealth of C. baccatum PEN45 we combined interspecific crossing with embryo rescue, resulting in a multi-parent BC2S1 population, that was characterized for sensory and biochemical variation (Chapter 5). We developed a population specific genetic linkage map for QTL mapping of characterized traits. Because of the complex structure of our BC2S1 mapping population we encountered several limitations, such as accidental co-segregation, underrepresentation of color linked markers and pre-selection leading to skewness, which might have resulted in false positive or missed QTLs. Despite these limitations, we were still fairly well able to map several biochemical, physical and sensory traits, as demonstrated at first for the (monogenic) control traits red color and pungency in the BC2S1 mapping population and in second instance by validation of genetic effects via an experiment with near-isogenic lines (NILs).This two-step approach turned out to be very powerful, since it led to the identification of the main results from this thesis: (i) Asmall C. baccatum LG3 introgression causing an extraordinary effect on flavor, which resulted in significantly higher scores for the attributes aroma, flowers, spices, celery and chives. In an attempt to identify the responsible biochemical compounds few consistently up- and down-regulated metabolites were detected, including the well-known pepper compound 2-isobutyl-3-methoxypyrazine (down) and 6-methyl-4-oxo-5-heptenal (up); (ii) Two introgressions (LG10.1 and LG1) had major effects on terpenoid content of mature fruits, affecting at least fifteen different monoterpenes; (iii) A second LG3 fragment resulted in a strong increase in Brix (total soluble solids) without negative effects on fruit size (Chapter 5).

    In Chapter 6 some extra sensory results of the pungent genotypes are given and a comparison between the two C. baccatum pendulum BILs (PEN45 and PEN79 derived) is made in light of the overall results. Finally the perspectives for breeding are discussed and presented in the form of a flowchart for flavor improvement.

    Authenticiteit van Boeren-Leidse kaas : analytische test om kaas met beschermde oorsprong te verifiëren
    Ruth, S.M. van - \ 2012
    Wageningen : RIKILT - Intstitute of Food Safety
    kazen - voedselanalyse - voedseltechnologie - streekgebonden producten - massaspectrometrie - geur en smaak - authenticiteit - cheeses - food analysis - food technology - regional specialty products - mass spectrometry - flavour - authenticity
    Binnen het onderzoeksinstituut RIKILT, onderdeel van Wageningen University & Research Centre, is een methode ontwikkeld om de identiteit van de Europees beschermde oorsprongsbenamingskaas 'Boeren-Leidse kaas met sleutels' te kunnen typeren en te verifiëren. De vingerafdruk van de vluchtige stoffen (het aroma) van de kaas wordt hierbij gebruikt om onderscheid te maken tussen Boeren-Leidse kaas met sleutels en andere komijnekazen met vergelijkbaar vetgehalte en rijpingsduur. De niet-destructieve methode behoeft een snelle scan van de lucht boven de kaas met behulp van Proton Transfer Reaction Mass Spectrometry. De fingerprints worden opgeslagen in een database en uiteindelijk vergeleken met behulp van statistische methoden.
    Texture, energy density & learning : implications for food intake
    Hogenkamp, P.S. - \ 2012
    Wageningen University. Promotor(en): Kees de Graaf, co-promotor(en): A. Stafleu; Monica Mars. - S.l. : s.n. - ISBN 9789461731227 - 143
    voedselopname - verzadigdheid - energieopname - textuur - viscositeit - geur en smaak - leren - food intake - satiety - energy intake - texture - viscosity - flavour - learning

    Food texture has been shown to be an important factor in the regulation of food (energy) intake. Liquid foods e.g. elicit weaker satiety responses than solid foods with a similar energy content, and texture affects satiation, i.e. ad libitum food intake. Whether theeffect of food texture on food intake stays the same over repeated exposure requires further investigation.
    The aim of this thesis is to investigate the role of food texture in learned satiation. We assessed the effect of texture on changes in ad libitum intake and expected satiation after repeated consumption of foods with different energy density.
    We conducted a series of learning experiments with healthy young adults. Participants repeatedly consumed a low-energy-dense (LED) and a high-energy-dense (HED) yogurt, which were either low (n=24) or high (n=22) in viscosity in one study; and consumed with a straw (liquid yogurt, n=34) or with a spoon (liquid yogurt, n=36; semi-solid yogurt, n=35) in a second study.
    Next, we investigated changes in expected satiation and intake after repeated consumption of a LED soup (n=32) or a HED soup (n=32) with similar appearance; and of a liquid and a semi-solid custard with a similar energy density (n=53). Additionally, we assessed the effect of texture, flavour and means of consumption on expected satiation of iso-caloric dairy products in 3 single-meal experiments.
    Finally, we served a fixed amount of a LED or HED food - either liquid or semi-solid - at each meal on 3 consecutive days, and measured ad libitum buffet intake directly after consumption of these foods (n=27).

    Texture clearly affected satiation:ad libitum intake was up to 30% higher of liquid foods when compared with semi-solids foods in all experiments (p<0.0001). Participants expected semi-solid foods to be more satiating than iso-caloric liquid foods (p<0.01), irrespective of the product’s flavour or its means of consumption. The texture of a fixed amount of food did not affect subsequent intake of other foods.

    Participants were able to learn about the foods’ satiating capacity after repeated consumption. Ad libitum intake of a HED high-viscous yogurt decreased and was 10% lower compared with a LED high-viscous yogurt after repeated consumption, while intake of a LED and HED low-viscous yogurt did not differ (interaction effect: p=0.04). We also observed thatappetite sensations changed when participants repeatedly consumed a liquid and semi-solid custard with a similar energy density (p<0.05). In addition, participants increased their intake from the ad libitum buffet after repeated consumption of a LED food (from 1745 ± 577 to 1979 ± 567 kcal), while their intake did not change after a HED food (interaction effect: p=0.02). This increase was observed irrespective of the texture of the test foods.
    Ad libitum intake was higher of liquid foods when compared with semi-solid foods, also after learning about the energy content of a food over repeated exposure.
    Participants did not adjust their intake and expected satiation consistently. Intake did not change when participants consumed a LED and a HED yogurt with a straw or with a spoon. We also did not observe profound changes in the expected satiation of a LED and HED soup or a liquid and semi-solid custard.
    Healthy young adults learned about the foods’ satiating capacity after repeated consumption. Changes in intake and expectations in response to learning did not depend on food texture.
    Food intake and expected satiation were not easily changed. The effect of food texture on satiation is important in the regulation of food intake, also after repeated exposure.

    Vingerafdruk Boeren-Leidse
    Galle, S. ; Ruth, S.M. van - \ 2010
    De zelfkazer 62 (2010)6. - ISSN 0166-4549 - p. 13 - 13.
    kazen - smaak - geur en smaak - kaaskwaliteit - cheeses - taste - flavour - cheese quality
    Boeren-Leidse kaas met sleutels is een komijnekaas voor liefhebbers van een stevige textuur en een unieke smaak/aroma. De vluchtige (aroma)stoffen van de kaas zijn zo karakteristiek dat ze als een vingerafdruk van de kaas gebruikt kunnen worden om de ‘echte’ Boeren-Leidse met sleutels te onderscheiden van andere komijnekazen. Dat blijkt uit metingen van het RIKILT.
    Weinig suiker, veel smaak: geur versterkt de zoete smaak van appelsap
    Knoop, J.E. ; Smit, G. ; Bult, J.H.F. ; Stieger, M.A. - \ 2009
    Voedingsmiddelentechnologie 42 (2009)14/15. - ISSN 0042-7934 - p. 26 - 28.
    suikergehalte - suiker - appelsap - geur en smaak - productontwikkeling - geurstoffen - sugar content - sugar - apple juice - flavour - product development - odours
    Vermindering van het suikergehalte van voedingsmiddelen en dranken is met geuren te compenseren. TIFN, WUR en NIZO food research deden onderzoek naar appelsap. Optimalisatie van de combinatie van geurstoffen die van nature in het product voorkomen (clean label!) maakte een suikerreductie van 12% mogelijk zonder dat het sap minder zoet smaakte
    Smaakvolle producten voor een betere afzet
    Verkerke, W. - \ 2009
    BioKennis bericht Markt & Keten (2009)6. - 4
    biologische landbouw - biologische voedingsmiddelen - geur en smaak - smaak - marketingkanalen - consumentengedrag - organic farming - organic foods - flavour - taste - marketing channels - consumer behaviour
    De biologische sector wil gezonde en lekkere producten leveren die op duurzame wijze zijn geproduceerd. Wetenschappelijk onderzoek naar smaak kan de biologische keten helpen om dit doel te bereiken. Welke mogelijkheden zijn er om de smaak van biologische producten te verbeteren? Hoe scheid je het kaf van het koren? En hoe is die betere smaak vervolgens te vermarkten? In 20 jaar onderzoek is veel ervaring opgedaan
    Een kwestie van smaak
    Smit, G. - \ 2007
    Wageningen : Wageningen UR - 31
    smaak - geur en smaak - geurstoffen en smaakstoffen - receptoren - smaakonderzoek - taste - flavour - flavour compounds - receptors - taste research
    Sensory and instrumental analysis of food aromas
    Bult, J.H.F. - \ 2006
    Wageningen University. Promotor(en): J.H.A. Kroeze; Fons Voragen, co-promotor(en): H.N.J. Schifferstein; J.P. Roozen. - [S.l.] : S.n. - ISBN 9789085045236 - 172
    aroma - aromatische verbindingen - geur en smaak - geurstoffen en smaakstoffen - zintuiglijke waarneming - sensorische evaluatie - gaschromatografie - aroma - aromatic compounds - flavour - flavour compounds - organolepsis - sensory evaluation - gas chromatography

    Food aromas are generally perceived as unitary aromas, i.e. fried potatoes smell like fried potatoes and roasted coffee smells like roasted coffee. Nonetheless, nearly all food aromas are produced by a multitude of volatile components that contribute to an extensive collection of aromas in various compositions. Of the hundreds of volatiles released from fried potatoes and roasted coffee a major se!ection does not produce an odour, many others do produce an odour that contributes to one of both aromas, many others contribute to both. In spite of this, food aromas are not being perceived as collections of discernable odours.

    Central theme of this thesis is a method used to fractionate, identify and characterise the odorous components in mixtures of odorants: gas chromatography olfactometry (GCO). GCO entails the pressurised transfer of volatiles through a capillary column, after capturing these from the headspace of a foodstuff. Since the column delays volatiles differentially, panellists may sniff these volatiles sequentially on their release from the capillary. This allows the separate sensory evaluation of components in the aroma mixture.

    A well-established practice in technological studies is that measurement reliability of instruments is estimated and minimised. Although sniffing panels are generally employed as instruments that assess the odour impact of chemical components in food aromas, reliability assessment is generally not applied to their application. Paradoxically, there are no practically available valid methods that may assess the reliability of panel responses. In addition, studies of systematic bias of panel responses in GCO studies are not available, although some common assumptions in GCO studies are not valid psychologically. For instance, intense odorants that arc qualitatively similar to the aroma quality are generally identified as character impact components. However, perception studies showed that odorants may affect (viz. suppress) each others odour contribution in a mixture. Therefore, assumptions regarding the contribution of singular odorants to aromas on basis of GCO, is premature.

    This thesis introduces methodology to estimate GCO response reliability and reports the empirical testing of this methodology (chapters 2, 3 and 4). In addition, several GCO assumptions considered psychologically disputable, are evaluated in empirical studies. These studies entail the effect of stimulus context on the estimated reliability of GCO results (chapter 4), the evaluation of the contribution of GCO-identified 'character impact components' to an apple model aroma (chapter 5), the effects of task instruction on the identification of odorants in food aromas (chapter 6), the effects of peri-threshold components on a supra-threshold food aroma (chapter 7) and the effects of sequentially presented odorants on their mutual odour intensities as a function of qualitative odour similarity (chapter 8). The general conclusions of this thesis are, that panel responses in the temporary absence of odorants must be used to estimate the reliability of panel odour detections, and that mechanisms that systematically affect response variation should be known and considered m GCO.

    Flavour aspects of pea and its protein preparations in relation to novel protein foods
    Heng, L. - \ 2005
    Wageningen University. Promotor(en): Fons Voragen; Tiny van Boekel, co-promotor(en): Jean-Paul Vincken. - Wageningen : Wageningen University - ISBN 9789085041986 - 152
    erwten - pisum sativum - peulvruchteiwit - geur en smaak - aroma - vluchtige verbindingen - geurstoffen en smaakstoffen - saponinen - nieuwe voedingsmiddelen - peas - pisum sativum - legume protein - flavour - aroma - volatile compounds - flavour compounds - saponins - novel foods
    This research is part of the multidisciplinary program, PROFETAS (PROtein Foods Environment Technology And Society), which aimed to feasibly shift from animal proteins to pea proteins for the development of Novel Protein Foods (NPFs) with desirable flavour. The aim of this research is to investigate the flavour aspects of peas and its protein fractions, as being potential ingredients for NPFs. To achieve this objective, the type and amount of flavour compounds from pea flour and pea protein preparations, as well as the stability and sensory characteristics of some of these compounds were investigated. The interactions of flavour compounds and pea protein fractions, as well as the effect of heating and presence of non-protein components on these interactions were also studied. With the results obtained, PROFETAS will be able to provide essential information for food industries and research institutes, to aid in the production of food with superior quality. Food manufacturers can better manipulate their ingredients and processing, optimising production conditions, which in turn lead to cost saving.
    Process innovation and quality aspects of French fries
    Loon, W.A.M. - \ 2005
    Wageningen University. Promotor(en): Fons Voragen, co-promotor(en): Jozef Linssen. - Wageningen : Wageningen University - ISBN 9789085042105 - 156
    patates frites - verwerkingskwaliteit - kwaliteit voor voedselverwerking - stomen - textuur - geur en smaak - zintuiglijke waarneming - chips (French fries) - processing quality - food processing quality - steaming - texture - flavour - organolepsis
    The development and evaluation of a new production process for French fries is described. Superheated steam was used to replace pre-drying in hot air and par-frying in oil, and vacuum cooling was used for cooling and freezing. Finish-frying was still carried out in oil. In this way a substantial reduction of energy use and environmental costs was possible. However, problems with product quality were encountered. The main problem was skin formation, which resulted in a tough crust with a fatty appearance after finish-frying. The new process was modified, and this improved the product quality considerably. Unfortunately, the resulting energy reduction was too limited to justify the investment required for the new process.

    Furthermore, a new look into the quality aspects of French fries is presented using state-of-the-art equipment. A combination of sensory analysis, TextureAnalyser,andConfocalScanning Laser Microscopy was used to study crispness of French fries independent of moisture content and doneness. In this way a higher frying temperature was shown to increase crispness. Prolonged pre-drying in hot air caused blister formation, which was similar to the skin observed with superheated steam. Odour active compounds of French fries were identified using GC-MS and GC-Olfactometry. Subsequently, the release of some of these compounds was followed in real time with MS-Nose using assessors and a mouth model system. It was shown that increasing the frying time, adding salt, and also skin formation affect flavour release. Most of the identified flavour compounds originated either from theMaillardreaction or from lipid degradation.Acrylamideis formed in theMaillardreaction as well.Multiresponsemodelling ofacrylamideformation in a glucose-asparaginereaction system showed thatacrylamideis an intermediate rather than an end product. Early lipid oxidation was studied at frying conditions by following the decrease of the antiradical power. Frying French fries was found to slow down the decrease of antiradical power, suggesting that compounds withantioxidativeproperties migrate from the product to the oil.

    In conclusion, the work described in this thesis has contributed to insights into physicochemical processes that occur in French fries on micro-scale, and how process conditions influence the product quality.

    Comments of RIVO to the report "Bromophenols: cause off-flavour in marinated herring and other foods"
    Schelvis-Smit, A.A.M. ; Kotterman, M.J.J. - \ 2005
    onbekend : RIVO Milieu en Voedselveiligheid (Report / RIVO-Netherlands Institute for Fisheries Research no. C002/05) - 8
    geur en smaak - geurstoffen en smaakstoffen - visproducten - haringen - zuren - marineren - flavour - flavour compounds - fish products - herrings - acids - marinating
    In commission of GAB Robins Scully Tyrrell Ltd RIVO has evaluated the report of Jan W. Henfling. Identified in the documentation with nr: 1740-1747 + 1749-1756 + 1758-1759 RIVO has dealt mainly with those topics and opinions that are plainly not correct, not justifiable or misleading. Topics or opinions raised by Jan W. Henfling, which are not discussed in this RIVO report, do not necessarily reflect the opinion of RIVO. In this evaluation, the report will be discussed page by page. Again, it has never been scientifically proven that phenol in acetic acid was the cause of off-flavour in fishery products. To the opinion of RIVO the final conclusion in the Henfling-report is not stated by any solid evidence.
    Voedsel als uitdrukking van een levenswijze? Een sociologische benadering
    Dagevos, H. - \ 2004
    Tijdschrift voor sociaalwetenschappelijk onderzoek van de landbouw 19 (2004). - ISSN 0921-481X - p. 187 - 188.
    voedingsmiddelen - voedselkwaliteit - voedselconsumptie - smaak - geur en smaak - consumptiepatronen - houding van consumenten - boekbesprekingen - fast foods - kritiek - foods - food quality - food consumption - taste - flavour - consumption patterns - consumer attitudes - fast foods - book reviews - criticism
    Boekbespreking van een bundeling van artikelen van Schouten, die in 1998 t/m 2003 in Vrij Nederland zijn verschenen; met hierin een kritische kijk op de smaak van het tegenwoordige voedsel, de fastfoodcultuur, en de zuinigheid van consumenten wat betreft voedselkeuze
    Sweet and sour taste preferences of children
    Liem, D.G. - \ 2004
    Wageningen University. Promotor(en): Frans Kok, co-promotor(en): Kees de Graaf. - [S.I.] : S.n. - ISBN 9789085041054 - 200
    consumptiepatronen - kinderen - voedselvoorkeuren - smaken - smaakgevoeligheid - zintuiglijke waarneming - zoetheid - zuurgraad - geur en smaak - consumption patterns - children - food preferences - tastes - taste sensitivity - organolepsis - sweetness - acidity - flavour
    In the industrialized countries children have many foods to choose from, both healthy and unhealthy products, these choices mainly depend on children's taste preferences. The present thesis focused on preferences for sweet and sour taste of young children (4- to 12-years of age) living in the US and the Netherlands. Understanding how sweet and sour taste preferences are formed and modified can help health professionals and those working in industry, to develop strategies to decrease the consumption of sweet tasting foods and to increase the variety of children's diet with sour tasting foods. By using a variety of stimuli that differed in sweet (0.14M - 0.61M sucrose) and sour (0.00M - 0.25M citric acid) taste we investigated 1) how sweet and sour taste preferences of young children can be measured 2) which concentrations of sucrose and citric acid are most preferred 3) how repeated exposure modifies preferences and 4) how these preferences are related to oral physiological processes and food consumption. From the 7 studies we carried out it can be concluded that sweet and sour taste preferences of young children can consistently be measured with paired comparison and rank-order methods. Children prefer beverages with high concentrations of sucrose (0.61M) and a substantial part of children have a preference for extreme sour foods (0.08-0.25M citric acid). The later is related to intensity and novelty seeking behavior and consumption of fruits rather than oral physiological differences. Preferences for sour taste are related to exposure to sour taste during infancy and can not easily be changed by short repeated exposure during childhood. This is in contrast with preference for sweet taste, which can be heightened by a short repeated exposure during childhood. The knowledge gained by the present thesis may open the window to low-sweet and high-sour foods. This could be beneficial for fruit consumption and the dietary variety during childhood.
    Aromaonderzoek in de lift
    Kan, E.J.M. van; Boelrijk, A. - \ 2000
    Voedingsmiddelentechnologie 33 (2000)14/15. - ISSN 0042-7934 - p. 28 - 29.
    sensorische evaluatie - organoleptische kenmerken - geur en smaak - geurstoffen en smaakstoffen - aromatische stoffen - reuk - smaak - voedselindustrie - voedseltechnologie - productontwikkeling - consumenten - consumentenvoorkeuren - aroma - chemotaxis - sensory evaluation - organoleptic traits - flavour - flavour compounds - flavourings - smell - taste - food industry - food technology - product development - consumers - consumer preferences
    Verslag van het in mei gehouden minisymposium te Wageningen. Het werd georganiseerd door de Vereniging voor Voedingsleer en Levensmiddelentechnologie
    Smaakonderzoek kan acceptatie voedingsmiddelen onderbouwen
    Zandstra, L. - \ 2000
    Voeding Nu 2 (2000)6. - ISSN 1389-7608 - p. 18 - 19.
    geur en smaak - smaak - voedingsmiddelen - voedsel - eigenschappen - voedingswaarde - voedselsamenstelling - voedselacceptatie - aanvaardbaarheid - nieuwe producten - flavour - taste - foods - food - properties - nutritive value - food composition - food acceptability - acceptability - new products
    Psychophysical evaluation of interactive effects between sweeteners and aroma compounds
    Nahon, D.F. - \ 1999
    Agricultural University. Promotor(en): A.G.J. Voragen; J.P. Roozen. - S.l. : Nahon - ISBN 9789058080851 - 145
    zoetstoffen - geur en smaak - sensorische evaluatie - frisdranken - aroma - sweeteners - flavour - sensory evaluation - soft drinks - aroma

    The presence of intense sweeteners in a light soft drink influences the preferences for, and the flavour profiles of these drinks to various extents, depending on the aroma and sweeteners present. In this study equisweet mixtures of sweeteners were composed at 10% Sucrose Equivalent Value. The sucrose/maltitol and sucrose/aspartame mixtures were additive, whereas equisweet binary sucrose/Na-cyclamate mixtures and ternary sucrose/aspartame/Na-cyclamate mixtures revealed synergistic effects.

    The synergy observed for the ternary mixture was a linear combination of the synergy of the binary mixtures. Sensory analysis (quantitative descriptive analysis) of different solutions containing sweetener mixtures and a water soluble orange aroma revealed that aspartame and Na-cyclamate both differed from sucrose on the attributes chemical and aftertaste. The addition of orange aroma levelled out the differences observed between the sweetener solutions.

    Instrumental analysis revealed that high sucrose concentrations changed the release of the volatile compounds, while Na-cyclamate did not show this effect. Modelling of volatile release showed that the gas/solution partition coefficient and the mass transfer coefficient are the main factors influencing the release.

    Volatile and non-volatile compounds in ripened cheese : their formation and their contribution to flavour
    Engels, W.J.M. - \ 1997
    Agricultural University. Promotor(en): A.G.J. Voragen; H. Gruppen; S. Visser. - S.l. : Engels - ISBN 9789054857808 - 129
    kazen - dierlijke producten - geur en smaak - aroma - smaak - cheeses - animal products - flavour - aroma - taste

    Flavour is one of the most important attributes of cheese. Cheese flavour is the result of the breakdown of milk protein, fat, lactose and citrate due to enzymes from milk, rennet and microorganisms during production and ripening of cheese. For a large part the development of flavour during the ripening of cheese is determined by the process of proteolysis of caseins. Over the past years proteolysis has been studied very extensively and as a result a wealth of information about this process has been obtained. The ultimate products of proteolysis, amino acids, are prime flavour precursors in cheese and the formation of a "correct" pool of free amino acids is essential for a balanced development of cheese flavour. Amino acids undergo enzymic as well as chemical conversions to essential flavour compounds. However, the formation of cheese flavour compounds by lactic acid bacteria and their enzymes probably is much more important than the formation of flavour compounds by pure chemical reactions, e.g. coupling of carbonyls with amino acids.

    Until recently, the role of mesophilic starter lactococci, as present in hard-type cheeses (e.g. Gouda), in the process of amino acid degradation was regarded to be limited. Nevertheless, Gouda cheese develops an intense flavour and numerous volatile compounds derived from catabolism of amino acids can be found in this type of cheese.

    The purpose of the research described in this thesis was to investigate flavour compounds in the water-soluble fraction of cheese and to elucidate the formation of some of these compounds by lactococcal enzymes.

    Chapter 2 describes the production of water-soluble fractions (WSFs) from various types of cheese and the subsequent fractionation of these WSFs by serial ultrafiltration (UF) with membranes of different molecular weight cut-off. As a result fractions containing water-soluble components of various molecular weights were obtained (UF<500 Da, 5005000 Da). Sensory analysis revealed that lowmolecular-weight (<500 Da) compounds were responsible for flavour in WSFs of Cheddar, Gouda, Gouda 20 +Gruyère, Maasdam, Parmesan and Proosdij cheese. The larger peptides and proteins in the UF>500 Da fractions did not contribute directly to the actual flavour of these cheeses, although some flavour attributes, e.g. bitter, are ascribed to larger peptides.

    The UF<500 Da fractions of the various cheeses include small peptides (probably not larger than tetra peptides), amino acids, fatty acids and further breakdown products of these compounds. In the WSFs of Gruyère, Proosdij and Parmesan cheese large amounts of small peptides and free amino acids were detected, probably due to the action of proteolytic enzymes from thermophilic lactobacilli.

    The direct contribution of free amino acids to the actual cheese flavour probably is limited. They more likely act as precursors for cheese flavour compounds. Our taste evaluation results with fractions containing mainly small peptides (<500 Da), obtained from WSF by Sephadex G-10 gel filtration (Gouda cheese) and Sep-Pak C 18 chromatography (various cheese-types), indicated that such peptides, together with amino acids, must be mainly responsible for basic flavours (e.g. brothy, savoury, sweet). There is not necessarily a relation between cheese flavour and concentration of total free amino acids.

    Free fatty acids were detected in relatively high amounts in WSF of Parmesan (butyric acid), Gruyère, (butyric and propionic acid) and Maasdam cheese (propionic acid). In these cheeses fatty acids probably play an important role in flavour.

    Chapter 3 describes the isolation, identification and possible origin of volatile compounds in the WSFs of 8 hard-type cheeses. The analysis was performed by gas chromatography-mass spectrometry. The cheeses used and the procedure for preparation of WSF (having a distinct cheese-like taste) were the same as applied in Chapter 2.

    The volatiles identified belonged to six major groups: fatty acids, esters, aldehydes, alcohols, ketones and sulphur compounds. The flavour attributes of various constituents of each of these groups have been described. Most of the compounds detected were present in the WSF of all eight types of cheese, although their concentrations showed distinct differences. From this it can be concluded that there is not a single compound or class of compounds which is responsible for the full flavour of cheese. Numerous volatile components contribute to the flavour of cheese and our results support the "component balance theory" postulated some 40 years ago. A consequence of this is that it is not possible to describe the flavour of cheese in precise chemical terms.

    A considerable portion of the volatiles identified during our study originated from fatty acids (e.g methyl ketones and secondary alcohols) and amino acids (e.g. branchedchain aldehydes and alcohols and sulphur compounds). The breakdown of fatty acids and amino acids is probably governed primarily by enzymic processes and the starter enzymes are a major source of the enzymes involved. Non-starter organisms (e.g. moulds and bacterial surface flora), present in certain types of cheese, naturally also contribute to the formation of flavour compounds.

    In hard-type cheeses, such as Gouda and Cheddar, proteolytic enzymes from mesophilic starter lactococci play a crucial role in the formation of free amino acids during ripening. The results of the study described in Chapter 4 indicate that enzymes from mesophilic lactococci are also very important for the formation of (volatile) flavour components from amino acids. In the literature little information is available concerning the significance of amino acid degradation by mesophilic starter bacteria, although the formation of flavour components by certain mesophilic starter strains has been reported.

    We incubated cell-free extract (CFE), containing all soluble enzymes from Lactococcus lactis subsp. cremoris B78, a Gouda cheese starter organism, with methionine, methionine-containing peptides (e.g. fragment α s1 -CN(f24-199) from α s1 -casein or a mixture of peptides of molecular weight 500 - 5000 Da isolated from Gouda cheese) and fragment α s1 -CN(f1-23) from α s1 -casein (containing no methionine). These peptides, but also methionine, in itself were tasteless. Sensory analysis showed that a cheese- like flavour only developed during the incubations with methionine and methionine-containing peptides. The formation of relatively large amounts of volatile sulphur compounds, such as dimethyldisulphide and dimethyltrisulphide, from methionine during these incubations could be demonstrated by gas chromatographymass spectrometry. The use of heat-treated CFE in incubation experiments with methionine did not result in formation of a cheese-like flavour indicating that enzymic activity is necessary. Apart from sulphur compounds other volatiles produced during incubation of CFE with amino acids were identified. An example is 3-methylbutanal originating from leucine.

    The experiments in Chapter 4 unquestionably demonstrated that the conversion of methionine by Lactococcus lactis subsp. cremoris B78 is, at least partially, an enzymic process. Chapters 5 and 6 describe the purification and characterization of enzymes from this organism involved in the conversion of methionine. Two enzymic routes for formation of volatile products from methionine were resolved and in Figure 1 the reactions identified and possible follow-up reactions are shown.

    A direct demethiolation reaction of methionine is performed by cystathionine β-lyase. This pyridoxal-5'-phosphate-dependent enzyme is able to catalyse α,β-elimination as well as α,γ-elimination reactions. The latter process (indicated in Figure I by dashed lines) results in the production of methanethiol, a very potent flavour compound, from methionine. The physiological role of cystathionine β-lyase is however the conversion of cystathionine during the process of methionine biosynthesis. Although cystathionine β-lyase prefers to catalyze the α,β-elimination reaction (e.g. on lanthionine and cystathionine) α,γ-elimination on methionine does occur under conditions prevailing in ripening cheese, such as a high salt concentration and a low pH. An enzyme similar to cystathionine β-lyase, cystathionine γ-lyase (γ-CTL) was purified from Lactococcus lactis subsp. cremoris SK11 by Bruinenberg et al. This enzyme only catalyses the α,γ-elimination of cystathionine and not α,β-elimination. SK11 γ-CTL is also able to convert methionine by α,γ-elimination. However, in contrast to the Lactococcus lactis subsp. cremoris B78 enzyme, SK11 γ-CTL is unable to degrade L-homoserine and shows relatively high (α,β-elimination activity) toward L- cysteine.

    Figure 1. Pathways of the formation of volatile sulphur compounds from methionine by enzymes from Lactococcus lactis subsp. cremoris .

    The transamination of methionine by branched-chain aminotransferases from Lactococcus lactis subsp. cremoris B78 provided evidence for the existence of an alternative route for the formation of volatile sulphur compounds. This route comprises the conversion of methionine to 4-methylthio-2-ketobutyric acid (KMBA) in the presence of an α-keto acid, e.g. α-ketoglutaric acid (Figure 1). The intermediate KMBA is converted to methanethiol, which can be further converted to other volatile compounds important for cheese flavour e.g. dimethyldisulphide and dimethyltrisulphide. The aminotransferases described in this thesis, AT-A and AT-B, have a broad substrate specificity for both the amino-group donor and the amino-group acceptor. Branched-chain amino acids and α-ketoglutaric acid respectively were the most preferred substrates in this respect. Recently Yvon et al. reported the purification and characterization of an aromatic-amino-acid-converting aminotransferase from Lactococcus lactis subsp. cremoris NCDO 763. The enzyme was able to convert aromatic amino acids but also leucine and methionine and an important role in cheese flavour formation was assumed.

    The route of conversion of KMBA is uncertain, however. In eukaryotes the decarboxylation of KMBA by a branched-chain 2-oxo dehydrogenase complex has been reported. The product of decarboxylation of KMBA, i.e. methional (see Figure 1), has been implicated as an important factor in cheese flavour. The route of breakdown of methional however remains uncertain; a direct conversion of KMBA to methanethiol cannot be ruled out (Figure 1). Although up to now we could not establish the formation of methional from KMBA (Figure 1), our experiments have shown that (a) methional is produced during incubation of CFE from Lactococcus lactis subsp. cremoris B78 with methionine and (b) enzymes from this organism are involved in the conversion of KMBA. The 20-37 % ammonium sulphate fraction obtained from CFE namely facilitated the breakdown of KMBA. Additional experiments showed that thiamine pyrophosphate, a cofactor required for activity of decarboxylases, stimulated the enzymic breakdown of KMBA.

    A transaminative route of degradation of leucine similar to that of methionine (i.e. comprising transamination and decarboxylation) was also suggested by Braun and Olson. The products ultimately produced were 3-methylbutanal and 3-methylbutanol. These compounds, together with analogous compounds produced from isoleucine and valine, are important flavour compounds in various types of cheese. Because the aminotransferases described in Chapter 6 also displayed high activities towards branched-chain amino acids and aldehydes were produced during incubation of CFE with amino acids, it seems that at least two enzymic steps (transamination and decarboxylation) in the catabolism of these amino acids and methionine are mediated by similar enzymes from Lactococcus lactis subsp. cremoris B78.

    In Chapter 7 the results are shown of some preliminary experiments with cheese pastes and curds aimed at testing the role of methionine in combination with starter enzymes under more practical conditions. The observed flavours in pastes to which CFE of Lactococcus lactis subsp. cremoris B78 had been added were definitely cheese-like and volatile degradation products of methionine were detected with the aid of gas chromatography. The cheese-like flavour of the curds to which CFE and methionine had been added was undoubtedly more intense after 13 weeks than that of regular 13-weeks old Gouda cheese. From the results it is concluded that enzymes in CFE are able to convert methionine in the cheese-like systems, despite the unfavourable conditions e.g. low pH and high salt concentration. This finding is in line with the results of Chapters 5 and 6 which show that both the branched-chain aminotransferases and cystathionine β-lyase are still active under conditions prevailing in cheese.

    The results obtained in this study demonstrate that:

    (a) The direct contribution of non-volatile compounds formed during the process of cheese ripening, e.g. amino acids and small peptides, to the actual cheese flavour is limited. Volatile compounds formed during the process of cheese ripening undoubtedly are crucial for a proper cheese flavour. These volatiles mainly originate from casein, fat, lactose and citrate.

    (b) Amino acid-converting enzymes from starter lactococci, present in hard-type cheeses such as Gouda, play an essential role in the formation of cheese flavours. Currently, the cloning of the genes coding for the enzymes discussed in this thesis is in progress. The construction of genetically modified strains will facilitate further studies to elucidate the importance of these enzymes during cheese ripening.

    Although evidence has been provided that in cheese-like systems conversion of methionine to methanethiol and dirmethyIdisulphide takes place, future studies have to focus on amino acid converting processes in cheese itself. For diversification of cheese flavour not only the conversion of methionine is of importance, but also the conversion of other amino acids present in ripening cheese. Another important aspect is the role of lysis of starter cells during ripening. To assure an adequate interaction between substrates and enzymes lysis of cells, leading to the release of intracellular enzymes into the cheese matrix, is considered to be essential.

    Kwaliteitsbeoordeling van visserijproducten
    Luten, J.B. - \ 1995
    Voeding 56 (1995)1/2. - ISSN 0042-7926 - p. 29 - 33.
    voedingsmiddelen - voedselbewaring - visproducten - visverwerkende industrie - conserven - vis - haringen - sensorische evaluatie - organoleptische kenmerken - dierlijke producten - geur en smaak - aroma - smaak - kwaliteit - vervalsing - besmetting - verouderen - gebreken - achteruitgang (deterioration) - zeevisserij - foods - food preservation - fish products - fish industry - preserves - fish - herrings - sensory evaluation - organoleptic traits - animal products - flavour - taste - quality - adulteration - contamination - aging - defects - deterioration - marine fisheries
    Het meten van biochemische parameters voor het vaststellen van de versheid van schol, tong en haring
    Vleeskwaliteit in relatie tot classificatiegegevens en uitsnijrendement bij kruislingstieren = Relationship of meat quality with EUROP - classification and meat yield for crossbred young bulls
    Schneijdenberg, T.C.H.G.P. ; Hoving - Bolink, A.H. ; Vries, A.W. de - \ 1994
    Zeist : ID-DLO, Vestiging Zeist (IVO - rapport B-383) - 30
    dierlijke producten - aroma - rundvlees - karkaskwaliteit - geur en smaak - slacht - smaak - malsheid - textuur - kalfsvlees - animal products - beef - carcass quality - flavour - slaughter - taste - tenderness - texture - veal
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