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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    Solute inclusion and freezing rate during progressive freeze concentration of sucrose and maltodextrin solutions
    Vuist, Jan Eise ; Boom, Remko M. ; Schutyser, Maarten A.I. - \ 2020
    Drying Technology (2020). - ISSN 0737-3937
    Freeze concentration - solute inclusion - sucrose

    Progressive freeze concentration is an alternative method to concentrate aqueous industrial streams compared to evaporation or membrane separation. In this research sucrose and maltodextrin solutions were concentrated in a stirred progressive freeze concentrator. The solute inclusion in the formed ice was studied using varying stirring speeds, initial concentrations and freezing plate temperatures. Under constant freezing plate temperature, a lower limit was found for the solute inclusions with increasing stirrer speeds. To improve the freeze concentration process, a decreasing temperature ramp was applied to the freezing plate. This yielded 2 to 3 times less solute inclusions in the ice, while maintaining similar ice yields.

    Is triose phosphate utilization involved in the feedback inhibition of photosynthesis in rice under conditions of sink limitation
    Fabre, Denis ; Yin, Xinyou ; Dingkuhn, Michael ; Clément-Vidal, Anne ; Roques, Sandrine ; Rouan, Lauriane ; Soutiras, Armelle ; Luquet, Delphine ; Lawson, Tracy - \ 2019
    Journal of Experimental Botany 70 (2019)20. - ISSN 0022-0957 - p. 5773 - 5785.
    Climate change - CO enrichment - photosynthesis - rice - sink feedback - source-sink - sucrose - triose phosphate utilization

    This study aimed to understand the physiological basis of rice photosynthetic response to C source-sink imbalances, focusing on the dynamics of the photosynthetic parameter triose phosphate utilization (TPU). Here, rice (Oriza sativa L.) indica cultivar IR64 were grown in controlled environment chambers under current ambient CO2 concentration until heading, and thereafter two CO2 treatments (400 and 800 μmol mol-1) were compared in the presence and absence of a panicle-pruning treatment modifying the C sink. At 2 weeks after heading, photosynthetic parameters derived from CO2 response curves, and non-structural carbohydrate content of flag leaf and internodes were measured three to four times of day. Spikelet number per panicle and flag leaf area on the main culm were recorded. Net C assimilation and TPU decreased progressively after midday in panicle-pruned plants, especially under 800 μmol mol-1 CO2. This TPU reduction was explained by sucrose accumulation in the flag leaf resulting from the sink limitation. Taking together, our findings suggest that TPU is involved in the regulation of photosynthesis in rice under elevated CO2 conditions, and that sink limitation effects should be considered in crop models.

    Small intestinal targets involved in food intake regulation : 'from nutrient to satiety signal'
    Ripken, D. - \ 2016
    Wageningen University. Promotor(en): Renger Witkamp; H.F.J. Hendriks. - Wageningen : Wageningen University - ISBN 9789462576438 - 180
    obesity - preventive nutrition - small intestine - ileum - duodenum - jejunum - satiety - appetite control - food intake - safflower oil - vagus nerve - casein - stevia rebaudiana - sucrose - macronutrients - serotonin - animal models - human feeding - obesitas - preventieve voeding - dunne darm - ileum - duodenum - jejunum - verzadigdheid - eetlustcontrole - voedselopname - saffloerolie - nervus vagus - caseïne - stevia rebaudiana - sucrose - macronutriënten - serotonine - diermodellen - humane voeding

    Background and aim: The worldwide increasing prevalence of overweight and obesity raises concerns for health. There is a clear need for preventive strategies, because current preventative interventions have proven to be unsuccessful in the long term. New strategies may be developed based on targets in the small intestine by activating satiety signals. The thesis aimed to investigate small intestinal targets contributing to food intake regulation. These targets included serotonin, the vagal nerve and the intestinal brake mechanism.

    Methods: The effects of ileal stimulation with safflower oil (lipid mixture), casein (protein), sucrose (carbohydrate) and rebaudioside A (non-caloric sweetener) on GLP-1 and PYY release were investigated by applying an porcine ex vivo intestinal segment model. The same model was also used to investigate if serotonin is involved in (non-)nutritional-induced GLP-1 and PYY release.

    The contribution to satiation of GLP-1 and CCK receptors at the vagal nerve, was studied by investigating the effects of GLP-1 and CCK receptor antagonists on ad libitum food intake in a pig model of subdiaphragmatic vagotomy.

    Two placebo controlled randomized crossover studies were performed in healthy volunteers to investigate the effects of small intestinal macronutrient delivery on ad libitum food intake and satiety signals. The first study compared the effects of duodenal, jejunal and ileal casein delivery on ad libitum food intake and satiety signals. The second study investigated if ileal delivery of all three macronutrients results in activation of satiety signals and reduction in ad libitum food intake. In addition, it was investigated if ileal delivery of native casein is efficiently digested and absorbed and does not result in adverse effects. In both studies the nutrients were delivered to the small intestine by inserting a nasointestinal feeding tube in healthy volunteers.

    Results: All macronutrients and rebaudioside A stimulated GLP-1 and PYY release from ileal tissue segments. Protein and fat stimulated serotonin release. Inhibiting the reuptake of serotonin resulted in enhanced nutrient induced GLP-1, PYY and CCK release. Serotonin stimulated GLP-1 release from enteroendocrine cells via a serotonin receptor mediated process.

    Results of the in vivo pig study showed that antagonism of the CCK receptor increased food intake in both vagotomized and sham operated pigs. Blocking the GLP-1 receptor did not affect food intake in both groups.

    The human studies showed that ileal protein delivery inhibited food intake and activated satiety signals as compared to duodenal or jejunal protein delivery. Also, ileal delivery of small quantities (51.7 kcal) of each macronutrient decreased food intake and activated satiety signals. In addition, it was shown that ileal delivery of native casein resulted in a time and concentration depended increase in plasma concentrations of amino acids and did not result in activation of immune responses nor in gastrointestinal complaints.

    Conclusions: The data presented in this thesis show that ileal delivery of all macronutrients results in activation of satiety signals and reduction of food intake. Stimulation of the ileum resulted in the strongest activation of satiety signals and inhibition of food intake compared to duodenal and jejunal stimulation. Besides direct nutrient-receptor interaction, the ileum senses (non-)nutritional stimuli via serotonin mediated processes resulting in GLP-1 release. In conclusion, these results demonstrate that targeting the ileum with small amounts of macronutrients is safe and has potential as a weight management strategy.

    Effects of salt on the expansion of starchy snacks: a multiscale analysis
    Sman, R.G.M. van der; Broeze, J. - \ 2014
    Food & Function 5 (2014)12. - ISSN 2042-6496 - p. 3076 - 3082.
    glass-transition - sodium-chloride - aqueous-solutions - mass-transfer - sucrose - extrusion - potato - water - trehalose - mixtures
    We investigate the effect of salt on the expansion of starchy snacks during frying by means of a multiscale simulation model. This model has been developed earlier for starchy snacks without salt. The simulation results are analysed by means of the supplemented state diagram. We have found that the optimal expansion for salty snacks occurs under the same conditions as for snacks without salt. This occurs at the moisture content where the 4 bar boiling line intersects the critical isoviscosity line of 1 MPa s. Salt is shown to influence both the boiling line and the critical isoviscosity line, via a change of the glass transition. The optimal moisture content for salty snacks is lower than that of unsalted snacks. We view our findings as important for reformulations of starchy snacks with lower salt levels. Furthermore, the presented tools of the multiscale simulations and supplemented state diagram can generally be used for reformulation problems in structured foods.
    Nutrition and cognition in older adults : studies on the role of glucose, sucrose, protein, vitamin B12 and folic acid
    Zwaluw, N.L. van der - \ 2014
    Wageningen University. Promotor(en): Lisette de Groot, co-promotor(en): Ondine van de Rest; Rosalie Dhonukshe-Rutten. - Wageningen : Wageningen University - ISBN 9789462571075 - 184
    ouderenvoeding - voeding - ouderen - kenvermogen - glucose - sucrose - eiwittoevoegingen - vitamine b12 - dementie - elderly nutrition - nutrition - elderly - cognition - glucose - sucrose - protein supplements - vitamin b12 - dementia

    The age-related cognitive decline and the increase in dementia patients are large problems in societies with growing ageing populations. No cure is present for dementia, while the available medication only focuses on alleviating symptoms. It is therefore of major importance to find risk factors that can modify the development of cognitive decline and dementia. Pre-clinical and observational studies suggest a role for nutrients. Evidence derived from randomized controlled trials (RCTs) is, however, limited and equivocal with most studies showing no effect and only a few studies showing a beneficial effect of a nutritional intervention. In the current thesis, we investigated the acute and longer-term effects of different nutrients, i.e. glucose and sucrose, protein, resistance-type exercise training with or without protein, and vitamin B12 and folic acid in order to optimize and preserve cognitive functions in non-demented elderly people.

    A comprehensive literature review was performed on the acute effects of glucose and sucrose on cognitive performance (Chapter 2). Glucose is the most important fuel for the brain, and as such, manipulation of the supply of glucose may affect cognitive functions. The main conclusion of our review was that a glucose load may have a short-term beneficial effect on episodic memory. Enhancing effects on other cognitive domains were less clear, partly due to the small number of studies examining these effects. Limited research was also done on the possible effects of sucrose on cognitive functions. Therefore, we investigated the acute effects of 50 g of glucose and 100 g of sucrose on a broad spectrum of cognitive functions reflecting performance on episodic memory, working memory, attention and information processing speed, and executive functions (Chapter 3). This was done by a cross-over study in 43 elderly participants who had self-reported memory complaints. In contrast to the conclusion of our review, we did not observe an effect of glucose or sucrose on episodic memory, though we showed a beneficial effect of sucrose on attention and information processing speed.

    Protein supplementation was the next nutritional intervention that was investigated. Several amino acids are precursors for neurotransmitters, and their supply may affect the synthesis and release of these neurotransmitters, and may consequently affect cognitive performance. A 24-week randomized placebo-controlled trial was carried out in 65 frail and pre-frail elderly people (Chapter 4). The protein supplementation included twice a day 15 grams of protein in the form of a drink. Reaction time improved more in the protein group compared to the placebo group, but the scores on the cognitive domains, i.e. episodic memory, attention and working memory, information processing speed, and executive functions, or the other single test scores, did not differ between treatment groups. In addition, we investigated the effects of 24 weeks resistance-type exercise training with and without protein supplementation in pre-frail and frail elderly people (Chapter 5). Exercise training without extra protein (n=62) improved performance on the domain attention and working memory. Exercise training together with protein supplementation (n=65) improved performance on information processing speed.

    Last, the role of vitamin B12 and folate on cognitive health was investigated. Low levels of these nutrients can increase homocysteine levels, which is a suggested risk factor for cognitive decline. The effect of daily supplementation with 500 µg vitamin B12 and 400 µg folic acid was investigated in 2,919 participants for two years (Chapter 6). Global cognitive function and episodic memory were assessed in the total study population, whereas extensive neuropsychological testing was done in a subpopulation (n=856). B-vitamin supplementation did not improve cognitive domain scores. Only a small, though significant, effect was observed on global cognitive performance, measured by the Mini-Mental State Examination, but this was suggested to be due to chance. Brain MRI scans were made in a subgroup (n=218) after two years of intervention to obtain volumetric measures of grey and white matter, and total brain volume (Chapter 7). We investigated the cross-sectional associations between follow-up levels of folate, homocysteine and three vitamin B12 status biomarkers, e.g. methylmalonic acid, holotranscobalamin and serum vitamin B12, and brain volumes. Fully adjusted regression models showed a borderline significant association between plasma homocysteine and total brain volume, with a stronger association in the group that received B-vitamin supplementation. Serum B12 and holotranscobalamin were not associated with brain volumes, whereas high methylmalonic acid levels were associated with lower brain volumes in the group that received B-vitamins. In contrast, higher folate levels were associated with lower total brain volumes. In addition, when comparing the group that received two years of B-vitamin supplementation and those who did not, we observed lower brain volumes in the B-vitamin group, which might be a result of a difference in age between the two groups.

    To conclude, the nutritional intervention studies showed little evidence for a beneficial effect on cognitive performance in relatively healthy older adults. Given the large problem of dementia, research on modifiable risk factors, including nutrition, should continue, with well thought out research methods, including large and long-term observational and intervention studies with high-sensitive study populations and early biomarkers (e.g. imaging techniques) for cognitive decline in combination with neuropsychological tests. In this way, nutrition can be added to the list of lifestyle factors that can fight dementia.

    Rheological behaviour of fibre-rich plant materials in fat-based food systems
    Bonarius, G.A. ; Vieira, J.B. ; Goot, A.J. van der; Bodnar, I. - \ 2014
    Food Hydrocolloids 40 (2014). - ISSN 0268-005X - p. 254 - 261.
    suspension rheology - sugar dispersions - chocolate - oils - emulsifiers - particles - sucrose - forces
    The potential use of fibre-rich materials as bulking agents to replace sucrose in chocolate confectionary products is investigated. Since the rheological behaviour of the molten chocolate mass is key in chocolate production, the rheology of fibre-rich materials in medium chain triglycerides (MCT) is studied and compared to the rheology of sucrose in MCT. The materials studied are side streams of the fruit and vegetable processing industry: lemon peels, spent grain, grape pomace and pecan fibre. All suspensions showed shear thinning behaviour at volume fractions >0.2, where side stream materials showed lower shear thinning behaviour than sucrose. The values for the maximum packing fraction, obtained via the Maron–Pierce equation and using the Casson Plastic Viscosities, were lower for the side stream materials than for sucrose. Addition of lecithin resulted in a decrease in the Casson Yield Value of sucrose suspensions, which was not observed with the fibre-rich materials. The rheological behaviour of the fibre-rich materials suspended in MCT is explained by the effective volume of the irregularly shaped particles. The behaviour of sucrose suspensions is explained by the formation of aggregates, which seem to be promoted by water bridges between the particles. Overall, the behaviour of the sucrose dispersions was very different compared to the other materials with respect to the shear thinning behaviour, the impact of lecithin as well as the impact of water. Therefore it is suggested that only partial replacement of sucrose by fibre-rich materials will be successful in industrial product development.
    Acrylamide and 5-hydroxymethylfurfural formation during baking of biscuits: NaCl and temperature-time profile effects and kinetics
    Fels, H.J. van der; Capuano, E. ; Nguyen, H.T. ; Mogol, B.A. ; Kocadagli, T. ; Goncuoglu Tas, N. ; Hamzalioglu, A. ; Boekel, M.A.J.S. van; Gokmen, V. - \ 2014
    Food Research International 57 (2014). - ISSN 0963-9969 - p. 210 - 217.
    aberrant crypt foci - maillard reaction - mass-spectrometry - model system - food - glucose - cookies - asparagine - sucrose - cancer
    The present study aimed to investigate the effect of recipe and temperature–time on the formation of acrylamide and 5-hydroxymethylfurfural (HMF) during biscuit baking. Baking experiments were performed with biscuits of two different recipes, with and without NaCl, at 180 °C, 190 °C and 200 °C. Acrylamide and HMF reached highest concentrations at 200 °C for both recipes. The presence of NaCl in the biscuit formulation lowered acrylamide concentrations at 180 °C and 190 °C but not at 200 °C, and led to higher concentrations of HMF at all the tested temperatures. Sucrose hydrolysis was a key step in acrylamide and HMF formation during biscuit baking, even though a significant amount of acrylamide already had formed before the onset of sucrose hydrolysis. A lag phase was observed before sucrose hydrolysis occurred, which might depend on the melting of crystalline sucrose occurring at approximately 180 °C. A mathematical model based on the chemical reaction pathways was developed for the recipe with NaCl baked at 200 °C. The model described the chemical evolution during the last part of biscuit baking, and accurately predicted acrylamide and HMF content at the end of baking. The model showed the significant contribution of the reducing sugars to the formation of both acrylamide and HMF. The model could not be extended to the entire baking period because it was not possible to incorporate the lag phase observed before sucrose hydrolysis. The results reported in this study confirm that the kinetics of acrylamide and HMF formation in real food and dry systems may depend on the physical state of their precursors.
    Expression of an amylosucrase gene in potato results in larger starch granules with novel properties
    Huang, X. ; Nazarian, F. ; Vincken, J.P. ; Ji, Q. ; Visser, R.G.F. ; Trindade, L.M. - \ 2014
    Planta 240 (2014)2. - ISSN 0032-0935 - p. 409 - 421.
    antisense inhibition - branching enzyme - tuber - synthase - glycogen - amylopectin - reduction - amylose - sucrose - size
    Main conclusion - Expression of amylosucrase in potato resulted in larger starch granules with rough surfaces and novel physico-chemical properties, including improved freeze–thaw stability, higher end viscosity, and better enzymatic digestibility. Starch is a very important carbohydrate in many food and non-food applications. In planta modification of starch by genetic engineering has significant economic and environmental benefits as it makes the chemical or physical post-harvest modification obsolete. An amylosucrase from Neisseria polysaccharea fused to a starch-binding domain (SBD) was introduced in two potato genetic backgrounds to synthesize starch granules with altered composition, and thereby to broaden starch applications. Expression of SBD–amylosucrase fusion protein in the amylose-containing potato resulted in starch granules with a rough surface, a twofold increase in median granule size, and altered physico-chemical properties including improved freeze–thaw stability, higher end viscosity, and better enzymatic digestibility. These effects are possibly a result of the physical interaction between amylosucrase and starch granules. The modified larger starches not only have great benefit to the potato starch industry by reducing losses during starch isolation, but also have an advantage in many food applications such as frozen food due to its extremely high freeze–thaw stability.
    Moisture sorption in mixtures of biopolymer, disaccharides and water
    Sman, R.G.M. van der - \ 2013
    Food Hydrocolloids 32 (2013)1. - ISSN 0268-005X - p. 186 - 194.
    glass-transition temperature - frozen state transitions - vapor sorption - poly(ethylene glycol) - amorphous mixtures - sucrose - behavior - prediction - polymers - crystallization
    The moisture sorption of ternary mixtures of biopolymer, sugar and water is investigated by means of the Free-Volume-Flory-Huggins (FVFH) theory. The earlier FVFH theory developed for binary mixtures of biopolymer/water and sugar/water has to be modified to account for two effects: 1) the change in the glass temperature due to the non-ideal mixing of biopolymer and 2) inhibition of self-association of the polymer if the mixture is quenched very fast into the glassy state. The modified FVFH theory forms a good basis for predicting moisture sorption for quaternary mixtures of biopolymers, di-, mono-saccharides and water - which can be viewed as a model for vegetables and fruits. (c) 2013 Elsevier Ltd. All rights reserved.
    Taste-nutrient relationships in commonly consumed foods
    Dongen, M.V. van; Berg, M.C. van den; Vink, N. ; Kok, F.J. ; Graaf, C. de - \ 2012
    The British journal of nutrition 108 (2012)1. - ISSN 0007-1145 - p. 140 - 147.
    body-weight - energy-balance - sweeteners - sucrose - flavor - intensity - receptors - nutrition - sweetness - behavior
    Taste is expected to represent a food's nutrient content. The objective was to investigate whether taste acts as nutrient-sensor, within the context of the current diet, which is high in processed foods. Intensities of the five basic tastes of fifty commonly consumed foods were rated by nineteen subjects (aged 21.0 (SD 1.7) years, BMI 21.5 (SD 2.0) kg/m(2)). Linear regression was used to test associations between taste and nutrient contents. Food groups based on taste were identified using cluster analysis; nutrient content was compared between food groups, using ANOVA. Sweetness was associated with mono- and disaccharides (R-2 0.45, P <0.01). Saltiness and savouriness were correlated, with r 0.92 (P
    Starch-related Enzymes during Potato Tuber Dormancy and Sprouting
    Sergeeva, L.I. ; Claassens, M.M.J. ; Jamar, D.C.L. ; Plas, L.H.W. van der; Vreugdenhil, D. - \ 2012
    Russian Journal of Plant Physiology 59 (2012)4. - ISSN 1021-4437 - p. 556 - 564.
    adp-glucose pyrophosphorylase - solanum-tuberosum - developmental-changes - hexose-phosphate - gene-expression - metabolism - sucrose - phosphorylase - biosynthesis - tuberization
    Activities of enzymes presumably involved in starch biosynthesis (ADP-glucose pyrophosphorylase, AGPase) and/or breakdown (starch phosphorylase, STP; amylases) were determined during potato (Solanum tuberosum L.) tuber dormancy and sprouting. Overall activities of all these enzymes decreased during the first stage of tuber dormancy. No clear changes were detected at the time of dormancy breaking and sprouting. However, when AGPase activity was monitored by in situ staining during the entire dormancy period, a clear decrease during the dormant period and a large increase before visible sprouting could be observed. This increase was especially evident near the vascular tissue and at the apical bud, which showed a very intensive staining. In situ staining of STP activity in sprouting tubers showed that the tissue distribution of STP was the same as for AGPase. As a possible explanation, direct starch cycling is suggested: STP produces glucose-1-phosphate during starch breakdown, which can be directly used as a substrate by AGPase for starch synthesis. Gene expression studies with the AGPaseS promoter coupled to the firefly luciferase reporter gene also clearly showed a higher activity in sprouting tubers as compared to dormant tubers, with the highest expression levels observed around the apical buds. The presence of amylase activity at dormancy initiation and AGPase activity persistent at the sprouting stage suggest that starch was cycling throughout the entire dormancy period. According to the in situ studies, the AGPase activity increased well before visible sprout growth and could therefore be one of the first physiological determinants of dormancy breakage.
    On the prediction of the remaining vase life of cut roses
    Tromp, S.O. ; Sman, R.G.M. van der; Vollebregt, H.M. ; Woltering, E.J. - \ 2012
    Postharvest Biology and Technology 70 (2012)aug.. - ISSN 0925-5214 - p. 42 - 50.
    vascular blockage - keeping quality - flowers - water - temperature - sucrose - storage - model
    The objective of the present paper was to examine the hypothesis that the time–temperature sum built up during storage and transport at constant as well as stepwise changing temperatures is a good predictor of the remaining vase life of cut roses. Theoretical calculations and graphing of functions showed that the time–temperature sum closely approximated the more common approach to quality loss, involving first order reaction kinetics with an Arrhenius temperature dependency. The time–temperature sum approximation failed at temperatures below 2 °C, especially in the case of long storage times. The time–temperature sum approximation succeeded in the range 2–6 °C. For temperatures above 6 °C, the degree-days model will underestimate the remaining vase life, depending on the storage time. The current experiment confirms these expectations from theory about the performance of the time–temperature sum. In the experiment not only constant storage temperatures but also stepwise changing storage temperatures were applied. Because of its simple principle, the time–temperature sum has practical value, but we are now aware of its limitations.
    Designing food structures to enhance sensory responses
    Mosca, A.C. - \ 2012
    Wageningen University. Promotor(en): Tiny van Boekel, co-promotor(en): Markus Stieger; F. van de Velde. - S.l. : s.n. - ISBN 9789461732477 - 164
    sucrose - vet - sensorische wetenschappen - smaakgevoeligheid - smaak - zintuiglijke waarneming - ruimtelijke verdeling - gels - mechanische eigenschappen - zoetheid - sucrose - fat - sensory sciences - taste sensitivity - taste - organolepsis - spatial distribution - gels - mechanical properties - sweetness

    Background and Aim

    The current overconsumption of sugar, salt and fat has been linked to the incidence of health problems. For this reason, it is necessary to decrease the intake of these food components. In the context of reducing the contents of sugar, salt and fat in food products while maintaining sensorial quality, the aim of this thesis was to identify and understand the factors that affect the perception of taste and fat-related sensory attributes in semi-solid foods. To achieve this aim, the relationship between the spatial distribution of sucrose, the mechanical properties of semi-solid gels and the perception of taste was investigated in detail. In addition, the relationship between the spatial distribution of fat and the perception of fat-related sensory attributes was investigated.

    Methods

    Model systems composed of layers of mixed agar-gelatin gels were used to control the spatial distribution of sucrose and fat. Layers varying in concentration of sucrose or oil-in-water emulsion droplets (i.e. fat) were combined to prepare gels with homogeneous and inhomogeneous distributions of sucrose and fat. A series of experiments were carried out using 2-Alternative Forced Choice (2-AFC) tests, line scale ratings and time-intensity analysis to investigate the effects of modulation of the spatial distribution of sucrose and modulation of the mechanical properties of gels on sweetness intensity. The relationship between the spatial distribution of tastants and consumer preference was investigated in different types of foods (e.g. semi-solid gels, breads and sausages). Furthermore, a Quantitative Descriptive Analysis (QDA) panel was carried out to investigate the effect of modulation of the spatial distribution of fat on the perception of fat-related sensory attributes.

    Results

    An inhomogeneous distribution of sucrose at large sucrose concentration differences enhanced sweetness intensity. The frequency of high-intensity discontinuous stimulation of taste receptors, which is related to the presence of tastant concentration differences in the mouth during oral processing, was identified as the driving factor for taste enhancement. The oral breakdown of semi-solid gels, which is affected mainly by fracture strain, and the mixing behavior of gel fragments formed upon breakdownwere shown to influence the frequency of receptor stimulation and, consequently, taste enhancement. Furthermore, the optimum frequency of high-intensity discontinuous stimulation required to maximize taste enhancement was shown to depend on the textural properties of the gel. These findings suggest that the spatial distribution of tastants and the mechanical properties (especially fracture strain) can be modulatedto maximize taste enhancement. Additionally, consumer preference was found to be maintained or increased in products containing tastants heterogeneously distributed in the food matrix.

    Fat-related mouthfeel attributes, such as spreadable and melting, were enhanced by an inhomogeneous distribution of fat at large fat concentration differences. The presence of high-fat zones on the surface of the model system was shown to maximize the enhancement of attributes related to fat. Therefore, the enhancement of fat-related attributes seems to be driven by the presence of high-fat zones preferably on the surface of the product rather than by the presence of fat concentration differences within the product.

    Conclusions

    The combined effects of modulation of the spatial distribution of tastants and fat and modulation of the mechanical properties can be applied in the development of low-sugar, low-salt and low-fat food products with improved taste quality.

    Proof of principle for the synthesis of hydroxy-aryl esters of glycosidic polyols and non-reducing oligosaccharides with subsequent enzymatic coupling to a tyrosine-containing tripeptide
    Haar, R. ter; Wildschut, J. ; Sugih, A.K. ; Moller, W.B. ; Waard, P. de; Boeriu, C.G. ; Heeres, H.J. ; Schols, H.A. ; Gruppen, H. - \ 2011
    Carbohydrate Research : an international journal 346 (2011)8. - ISSN 0008-6215 - p. 1005 - 1012.
    cross-linking - sucrose - acid - stability - starch - ph
    To enable enzymatic coupling of saccharides to proteins, several di- and trisaccharides were hydroxy-arylated using anhydrous transesterification with methyl 3-(4-hydroxyphenyl)propionate, catalyzed by potassium carbonate. This transesterification resulted in the attachment of up to 3 hydroxy-aryl units per oligosaccharide molecule, with the monosubstituted product being by far the most abundant. The alkaline reaction conditions, however, resulted in a partial breakdown of reducing sugars. This breakdown could easily be bypassed by a preceding sugar reduction step converting them to polyols. Hydroxy-arylated products were purified by using solid phase extraction, based on the number of hydroxy-aryl moieties attached. Monohydroxy-arylated saccharose was subsequently linked to a tyrosine-containing tripeptide using horseradish peroxidase, as monitored by LC–MSn. This proof of principle for peptide and protein glycation with a range of possible saccharides and glycosidic polyols can lead to products with unique new properties. Highlights ¿ Oligosaccharides and glycosidic polyols are hydroxy-arylated by transesterification. ¿ Hydroxy-arylated oligosaccharides are fractionated using solid phase extraction. ¿ Hydroxy-arylated saccharose is coupled to Gly-Tyr-Gly using horseradish peroxidase. ¿ Proof of principle given for protein glycation via an introduced phenolic linker.
    Prospects of utilization of sugar beet carbohydrates for biological hydrogen production in the EU
    Panagiotopoulos, I.A. ; Bakker, R.R. ; Vrije, G.J. de; Urbaniec, K. ; Koukios, E.G. ; Claassen, P.A.M. - \ 2010
    Journal of Cleaner Production 18 (2010)Supp.. 1. - ISSN 0959-6526 - p. S9 - S14.
    caldicellulosiruptor-saccharolyticus - pulp - biomass - bacterium - sucrose
    Hydrogen can be produced through dark anaerobic fermentation using carbohydrate-rich biomass, and through photofermentation using the organic acids produced from dark fermentation. Sugar beet is an ideal energy crop for fermentative production of hydrogen in the EU due to its environmental profile and its potential availability in the area. In this work, various aspects of cultivating sugar beet in the EU for biohydrogen were highlighted, with special focus on The Netherlands and Greece. Moreover, fermentation of sugar beet juice with Caldicellulosiruptor saccharolyticus at sucrose concentration 10 g/l was performed, and was found comparable to the fermentation on pure sucrose except that the hydrogen production was 10% higher on sugar beet juice. A conservative estimate of the annual hydrogen potential in the EU was made (300 × 106 kg hydrogen), considering the utilization of sugar beet pulp in hydrogen production.
    Effecten van eenvoudige koolhydraten en fermenteerbare koolhydraten op de binnentoom variatie bij varkens
    Wientjes, J.G.M. ; Soede, N.M. ; Brand, H. van den; Kemp, B. - \ 2010
    Wageningen : Adaptation Physiology Group, Wageningen University - 73
    varkens - zeugenvoeding - voersamenstelling - insuline - lactose - sucrose - suikerbieten - follikels - geboortegewicht - biggen - pigs - sow feeding - feed formulation - insulin - lactose - sucrose - sugarbeet - follicles - birth weight - piglets
    2 proeven werden uitgevoerd. Het doel van de 1e was nader inzicht te krijgen in het mechanisme dat ten grondslag ligt aan de relatie tussen insuline-stimulerend voer (dextrose+lactose) tijdens het interval spenenovulatie, follikelontwikkeling in de laatste dagen voor inseminatie en (variatie in) ontwikkeling van embryo's tijdens de vroege dracht. Het doel van de 2e proef was om nader inzicht te krijgen in de directe effecten van de specifieke voercomponenten dextrose, lactose, sucrose en suikerbietenpulp (zowel apart als gecombineerd) op glucose, insuline en IGF-1 profielen in zeugen om zo diëten te vinden met de hoogste potentie om insuline en IGF-1 afgifte te stimuleren.
    Effect of Disaccharides on Ion Properties in Milk-Based Systems
    Gao, R. ; Leeuwen, H.P. van; Temminghoff, E.J.M. ; Valenberg, H.J.F. van; Eisner, M.D. ; Boekel, M.A.J.S. van - \ 2010
    Journal of Agricultural and Food Chemistry 58 (2010)10. - ISSN 0021-8561 - p. 6449 - 6457.
    mean spherical approximation - nuclear-magnetic-resonance - activity-coefficients - primitive model - aqueous systems - sugar solutions - caprine casein - calcium-ion - electrolytes - sucrose
    The mean spherical approximation (MSA) theory is used to explain the impact of sugars on ion properties in milk-based systems by taking into account electrostatic interactions and volume exclusion effects. This study first focuses on the changes in Ca2+ activity and pH in a solution consisting of CaCl2, KCl, and K3citrate, as a function of sucrose concentration. MSA model calculations were compared with experimental results, and the model satisfactorily describes the ion properties. The excluded volume effects appear to account for a considerable increase in activity coefficient of the ions. This offers a sufficient explanation for the increase in Ca2+ activity and the decrease in pH in milk-based systems with added disaccharides. In addition, hydration of milk proteins seems to enhance ion pair formation in milk. All disaccharides lead to similar modification of the thermodynamic properties of milklike systems, confirming that the observed effects are primarily due to volume exclusion effects
    Molecular sieves provoke multiple substitutions in the enzymatic synthesis of fructose oligosaccharide–lauryl esters
    Haar, R. ter; Schols, H.A. ; Broek, L.A.M. van den; Saglam, D. ; Frissen, A.E. ; Boeriu, C.G. ; Gruppen, H. - \ 2010
    Journal of Molecular Catalysis. B, Enzymatic 62 (2010)2. - ISSN 1381-1177 - p. 183 - 189.
    regioselective acylation - organic media - esterification - lipase - sucrose - acid - hydrolases - cellulose - al-mcm-41 - zeolites
    The cause of discrepancies in the literature regarding the specificity of immobilized Candida antarctica lipase B in the acylation of oligosaccharides was examined. Molecular sieves, generally used to control the water content during acylation reactions, turned out to have an important role in this. It was proven that molecular sieves alone can catalyze the acylation of fructose oligomers using vinyl laurate, leading to multiple substitution of the oligomers. This effect was the most profound at conditions unfavorable for the enzyme, because this resulted in a relatively high concentration of the chemically produced adducts. The enzyme alone catalyzed the formation of monosubstituted oligomers. It was proven that even solvent pre-drying by molecular sieves already causes the release of catalyzing compounds to the liquid, leading to subsequent catalysis. These findings should be taken into account when applying molecular sieves in this type of reactions in the future. Molecular sieves could, moreover, be used as a catalyst when multiple substitution is desired.
    Endogenous and bioaugmented sulphate reduction in calcareous gypsiferous soils
    Alfaya, F. ; Cuenca-Sanchez, M. ; Garcia-Orenes, F. ; Lens, P.N.L. - \ 2009
    Environmental Technology 30 (2009)12. - ISSN 0959-3330 - p. 1305 - 1312.
    sludge bed reactors - granular sludge - reducing bacteria - anaerobic reactor - electron-donors - methanol - bioreactor - acetate - ethanol - sucrose
    Gypsiferous soils have a high agricultural value, but their utilization is limited by the presence of gypsum that can induce hardpan and vertical crusting. This paper reports on sulphate reduction in this soil type as a basis of a bioremediation technology to remove the gypsum content of calcareous gypsiferous soils. Both the endogenous and bioaugmented sulphate-reducing potential of the soil was assessed in anaerobic batch tests. An endogenous population of sulphate-reducing bacteria was found to be present in the calcareous gypsiferous soil investigated, which could form the basis of both in situ and ex situ bioremediation schemes for this soil type.
    Lignocellulosic ethanol in Brazil : technical assessment of 1st and 2nd generation sugarcane ethanol in a Brazilian setting
    Stojanovic, M. ; Bakker, R.R.C. - \ 2009
    Wageningen : Agrotechnology and Food Innovations - 18
    suikerriet - ethanol - lignocellulose - sucrose - fermentatie - technologie - brazilië - bioethanol - biobrandstoffen - sugarcane - ethanol - lignocellulose - sucrose - fermentation - technology - brazil - bioethanol - biofuels
    Brazil is currently the largest ethanol-biofuel producer worldwide. Ethanol is produced by fermenting the sucrose part of the sugarcane that contains only one third of the sugarcane energy. The rest of the plant is burned to produce energy to run the process and to generate electricity that is sold to the public grid, making the process a net energy producer. This paper evaluates current technology from an energy efficiency point of view and quantifies additional benefits from extra energy generated in during sugarcane processing.
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