Double emulsions as fat replacers : linking emulsion design to stability and sensory perception
Oppermann, Anika - \ 2017
Wageningen University. Promotor(en): Kees de Graaf, co-promotor(en): Markus Stieger; Elke Scholten. - Wageningen : Wageningen University - ISBN 9789463430722 - 186
fats - fat - sensory sciences - sensory evaluation - emulsions - perception - gelation - vetten - vet - sensorische wetenschappen - sensorische evaluatie - emulsies - perceptie - gelering
The use of double (w1/o/w2) emulsions, in which part of the oil is replaced by small water droplets, is a promising strategy to reduce oil content in food products. For successful applications, (1) significant levels of fat reduction (i.e. significant amounts of water inside the oil droplets) have to be achieved, (2) double emulsions have to be stable against conditions encountered during processing and storage, and (3) the mouthfeel and sensory perception have to be similar to that of full-fat equivalents. With the present work, significant progress was made in understanding the complex relations between double emulsion design, achievable levels of fat reduction, emulsion stability and sensory perception. We show that through careful emulsion design, stable double emulsions with high levels of fat reduction (up to 50%) can be obtained while maintaining fat-related sensory properties, making double emulsions a promising approach for the development of fat-reduced food products.
Dioxin monitoring in fats oils for the feed industry
Asselt, E.D. van; Sterrenburg, P. - \ 2011
Wageningen : Rikilt - Institute of Food Safety (Report / RIKILT, Institute of Food Safety 2011.004) - 37
dioxinen - monitoring - vetten - oliën - veevoederindustrie - analytische scheikunde - productieprocessen - voedselveiligheid - dioxins - monitoring - fats - oils - feed industry - analytical chemistry - production processes - food safety
The aim of the present project was to determine the most critical steps in the production of fats and oils. First, production processes of vegetables oils, animal fat, fish oil, biodiesel and fat blending were studied and experts from the industry as well as in-house dioxin experts were consulted to identify the most critical steps. Then, monitoring data for vegetable oil, animal fat and fish oil were analysed to determine which products have an increased risk of dioxin contamination.
Sturende factoren voor verhoging van vet- en eiwit gehalten in biologische melk : een eerste verkenning
Bont, J. ; Magendans, D. ; Nes, H. van; Oude Lenferink, K. ; Spit, J.J. ; Verkuijl, M. ; Louis Bolk, - \ 2009
Driebergen : Louis Bolk Instituut (Rapport / Biogeit 18) - 33 p.
geitenhouderij - geiten - biologische landbouw - diervoeding - eiwitten - vetten - genetica - goat keeping - goats - organic farming - animal nutrition - proteins - fats - genetics
The fat content in organic dairy goat's milk is significantly lower than milk of regular dairy goats. The difference in protein content between organic and regular goat farms is minimal. Statistical analysis shows that the fat content in the organic goat milk fluctuates more in relation to protein. To increase the level of fat and protein content in goat's milk, this report will show aspects regarding nutrition and genetics. Looking at the nutritional aspects of different fat and protein supplements and their effect on fat and protein content in goat's milk, a literature study into different supplements that are tested for their ability to increase the levels was executed. In addition, practical experiences of dairy goat farmers were collected and if possible supported by literature. The dietary ingredients that are dealt with are oils, seeds and beans and fats that bypass the rumen. One of the main conclusions is that almost all plant based dietary fats which are fed to the goats have an effect on the fat content in the milk, while the protein level remains mostly unchanged. These dietary fats seem promising. However, it is important that these fats are not used extensively. A level of fat that is too high will have a negative effect on the intake and digestibility in the rumen. Dietary fats with hay as basic feed will give better results than maize silage. An interaction between the species and the dietary fat seems obvious. It is interesting to think about possible effects of dietary fats in combination with various basic feeds. Experiments with seeds, beans and cakes have various results. Literature has shown that research is executed regarding whole seeds or oils. A recommendation is to investigate the influence of supplementation of 'intermediate forms' on fat and protein levels in goat milk, such as crushed and ground seeds. Most studies regarding rumen protected feeds lead to very positive results, because the nutrients are resistant against microbial degradation in the rumen. Because chemically protected feeds are not permitted in organic farming, one has to look for possibilities to make those feeds resistant in an organic manner. The solution seems to lie within the toasting of foods such as soybean, lupine and barley. Most experiments in this field have been done in dairy cattle and the results were promising. The effect of toasted feed in order to increase the milk composition of dairy goats needs attention. The literature shows that supplementation of crude protein has little or no effect on increasing protein levels in goat milk. Genetic progress can be achieved in organic goat when one breeds on fat and protein content. Looking at the different influences that genetics may have on the fat and protein contents of goat milk, it becomes clear that protein content in milk is determined by the casein genes. Through DNA research, the genetic potential of an animal can be proven. A high protein content has positive effects on fat content, but may have a negative impact on milk production. Also, the taste of goat cheese is influenced by a high protein content. The environmental factors of regular dairy goat farms differ from organic dairy goat farms. It is uncertain whether breeding bucks from the regular production system will have the same performance when used in organic dairy farms. Further research into genotype by environment interaction, in particular food and medication, may give more insight into the use of breeding goats from regular dairy goat farms in organic goat farming. Artificial insemination (AI) offers an opportunity for fresh and better genetic material to enter into the current herd. For AI, oestrus .......
The fate of fat: tribology, adhesion and fat perception of food emulsions
Dresselhuis, D.M. - \ 2008
Wageningen University. Promotor(en): Martien Cohen Stuart, co-promotor(en): E.H.A. de Hoog; G.A. van Aken. - [S.l.] : S.n. - ISBN 9789085048657 - 152
voedingsvet - vetten - emulsies - perceptie - tribologie - frictie - smering - adhesie - sensorische evaluatie - mond - orale biologie - dietary fat - fats - emulsions - perception - tribology - friction - lubrication - adhesion - sensory evaluation - mouth - oral biology
Met de toename van het aantal mensen met overgewicht neemt ook de vraag naar producten die minder vet bevatten, maar nog steeds wel een lekker smaak hebben toe. Om zulke producten te maken is het heel belangrijk te weten wat er tijdens consumptie met het product gebeurt en hoe mensen eigenlijk vet waarnemen. We hebben ons in ons onderzoek vooral gericht op de bijdrage van vet op wat we noemen het mondgevoel en hoe fysische chemische processen in de mond dit kunnen beïnvloeden. Allereerst hebben we vastgesteld dat mensen als ze tijdens en na het consumeren van een vloeibaar product een lage frictie waarnemen tussen tong en verhemelte, ze dit associëren met vet en romigheid. In het tweede deel van het onderzoek hebben we aanwijzingen gevonden hoe de capaciteit van levensmiddelen-emulsies om een smerende laag op de tong te vormen (en dus de frictie in de mond te verlagen), afhangt van de kans dat de emulsiedruppels plakken (adhesie) en kunnen spreiden op de tong. Met deze kennis over plakken en spreiden van emulsies op de tong kunnen we nu emulsies proberen te maken waarbij we meer efficiënt gebruik maken van de hoeveelheid vet in het product en dus mogelijkheden scheppen om het vetgehalte te verlagen zonder aan smaak in te boeten.
Bondt, N. ; Meeusen-van Onna, M.J.G. - \ 2008
Den Haag : LEI (Rapport / LEI : Domein 3, Natuurlijke hulpbronnen en milieu ) - ISBN 9789086152032 - 43
residuen - industrieel afval - afval - organisch afval - bijproducten - agrarische afvalstoffen - agro-industriële bijproducten - brandstoffen - vetten - technologie - plantaardige vetten - voedselindustrie - drankenindustrie - nederland - economische haalbaarheid - economische evaluatie - rentabiliteit - biobrandstoffen - bioethanol - biobased economy - residues - industrial wastes - wastes - organic wastes - byproducts - agricultural wastes - agroindustrial byproducts - fuels - fats - technology - plant fats - food industry - beverage industry - netherlands - economic viability - economic evaluation - profitability - biofuels - bioethanol - biobased economy
Dit rapport beschrijft de markt van reststromen uit de Nederlandse voedings- en genotmiddelenindustrie, en de aantrekkelijkheid van deze reststromen voor de productie van bioethanol en biodiesel. De eerstegeneratietechnologie kan slechts 29% van de 7,5 miljoen ton reststromen goed omzetten in biobrandstoffen. Als bovendien rekening wordt gehouden met niet-technische criteria blijken er voor bio-ethanol niet of nauwelijks reststromen interessant te zijn. Voor biodiesel kan wel gebruik worden gemaakt van de plantaardige en dierlijke vetten. De economische gevolgen voor onder meer de diervoedersector zijn beperkt. This report examines the market for residues from the Dutch food and beverage industry, and the appeal of these residues for the production of bio-ethanol and biodiesel. The firstgeneration technology is readily suited to the conversion of no more than 29% of the 7.5 million tonnes of residues into biofuels. Moreover, when non-technological criteria are also taken into account virtually none of the residues are of interest for conversion into bioethanol, although vegetable and animal fats can be used to produce biodiesel. The economic consequences for sectors such as the animal-feed sector are limited.
|Weinig eiwit nodig in rantsoen met graan
Klop, A. ; Plomp, M. - \ 2007
Ekoland 27 (2007)1. - ISSN 0926-9142 - p. 22 - 23.
melkveehouderij - voedering - voedingsrantsoenen - diergezondheid - graansoorten - tarwe - maïs - melkproductie - vetten - eiwitten - voeropname - melksamenstelling - biologische landbouw - dairy farming - feeding - feed rations - animal health - cereals - wheat - maize - milk production - fats - proteins - feed intake - milk composition - organic farming
Informatie uit onderzoek naar langetermijneffecten van gemalen tarwe als krachtvoervervanger. Veel voer van eigen bedrijf of eigen regio is een streven van veel biologische melkveehouders. Daarbij kunnen granen als krachtvoervervanger een belangrijke rol spelen. Bij goede opbrengsten kan zelf graan telen financieel aantrekkelijk zijn. Maar hoeveel graan kun je voeren zonder problemen met diergezondheid en eiwitvoorziening? Praktijkcentrum Aver Heino zocht naar de grenzen
The formation of fat-derived flavour compounds during the ripening of Gouda-type cheese
Alewijn, M. - \ 2006
Wageningen University. Promotor(en): J.T.M. Wouters, co-promotor(en): E.L. Sliwinski. - Wageningen : - ISBN 9789085043812 - 136
goudse kaas - geurstoffen en smaakstoffen - vetten - vetzuren - lactonen - esters - ketonen - kaasrijping - gouda cheese - flavour compounds - fats - fatty acids - lactones - esters - ketones - cheese ripening
Cheese flavour is an important quality attribute, and is mainly formed during cheese ripening. Besides compounds that are formed from protein and carbohydrates, milk fat-derived compounds are essential for cheese flavour. Before, but mainly during ripening, free fatty acids, lactones, ketones, esters, alcohols and aldehydes can be formed from milk fat, compounds that all contribute their own special character to the final cheese flavour. The formation mechanisms that lead to these compounds are not completely understood, and therefore cheese flavour formation is not under full control.
Voedingsmiddelenanalyses van de Afdeling Humane Voeiding. Deel 14 Vetzuursamenstelling van frituurvetten en bakkerijmargarines in Nederland in 2004
Hulshof, P.J.M. ; Kosmeyer, T. ; Siebelink, E. ; Katan, M.B. - \ 2005
Wageningen : Wageningen Universiteit, Sectie Humane voeding - 18
voedingsmiddelen - chemische samenstelling - vetten - oliën - bakoliën - bakvetten - boter - margarine - voedingswaarde - voedsel - voedselsamenstelling - kwaliteit - eigenschappen - huishoudens - ziekenhuizen - ziekenhuiscatering - verpleeghuizen - dierlijke producten - ingrediënten - Ghana - Filippijnen - spijsoliën - spijsvetten - institutionele huishoudens - foods - chemical composition - fats - oils - cooking oils - cooking fats - butter - margarine - nutritive value - food - food composition - quality - properties - households - hospitals - hospital catering - nursing homes - animal products - ingredients - Ghana - Philippines - edible oils - edible fats - institutional households
Borging van COKZ en uitgevoerd onderzoek door RIKILT : verordening (EG) nr 2571/97 bakkersboterregeling, periode: februari 2001 t/m november 2002
Labrijn, J.F. ; Berends, P.M. ; Boer, W.J. de - \ 2003
Wageningen : RIKILT (Report / RIKILT 2003.013) - 24
boter - vetten - voedselsamenstelling - analytische methoden - zuivelonderzoek - inspectie - nederland - wetgeving - butter - fats - food composition - analytical methods - dairy research - inspection - netherlands - legislation
|Vetoxidatie en het voorspellen van houdbaarheid
Dekker, M. - \ 2002
Voedingsmiddelentechnologie 35 (2002)1-2. - ISSN 0042-7934 - p. 37 - 39.
vetten - lipiden - geoxideerde vetten - oxidatie - chemische reacties - houdbaarheid (kwaliteit) - kwaliteit - bewaartijd - opslagkwaliteit - voedingsmiddelen - conferenties - fats - lipids - oxidized fats - oxidation - chemical reactions - keeping quality - quality - storage life - storage quality - foods - conferences
Verslag van een symposium als afsluiting van een onderzoeksproject
Effects of flavour absorption on foods and their packaging materials
Willige, R.W.G. van - \ 2002
Wageningen University. Promotor(en): A.G.J. Voragen; J.P.H. Linssen. - S.l. : S.n. - ISBN 9789058086402 - 140
geurstoffen en smaakstoffen - absorptie - verpakkingsmaterialen - voedselverpakking - eiwitten - koolhydraten - vetten - membraanpermeabiliteit - smaakpanels - modellen - flavour compounds - absorption - packaging materials - food packaging - proteins - carbohydrates - fats - membrane permeability - taste panels - models
Keywords: flavour absorption, scalping, packaging, food matrix, lldpe, ldpe, pp, pc, pet, pen,b-lactoglobulin, casein, pectin, cmc, lactose, saccharose, oil, modelling, storage, oxygen permeability, taste perception, sensory quality.
Absorption of flavour compounds by linear low-density polyethylene (LLDPE) was studied in model systems representing differences in composition of the food matrix. Proteins,b-lactoglobuline and casein, were able to bind flavours, resulting in suppression of absorption of flavour compounds. Polysaccharides, pectin and carboxymethylcellulose, increased viscosity, and consequently decreased absorption. Disaccharides, lactose and saccharose, increased absorption, probably caused by a "salting out" effect of less apolar flavour compounds. The presence of a relative small amount of oil (50 g/l) decreased absorption substantially. Combined oily model systems, oil/casein and oil/pectin, showed a similar effect. The extent of absorption of flavour compounds by LLDPE was influenced by food components in the order: oil or fat >> polysaccharides and proteins > disaccharides. A model based on the effect of the polarity (log P) of flavour compounds and on their partitioning coefficients between food(matrix) and packaging material was developed. The model is able to predict absorption of flavour compounds from foods into LLDPE when lipids in the food matrix are the determining factor in flavour absorption. Results show that the model fits nicely with experimental data of real foods skim and whole milk.
LLDPE, polypropylene (PP), polycarbonate (PC), polyethylene terephthalate (PET film and PET bottle) and polyethylene naphthalate (PEN) were immersed in a model flavour solution at different temperatures up to 14 days. The absorption rate and/or total amount of absorbed compounds increased considerably with increasing temperature. Depending on temperature, the total absorption of flavour compounds by the polyolefins (LLDPE and PP) was up to 2400 times higher than by the polyesters (PC, PET and PEN).
The effect of absorbed flavour compounds on the oxygen permeability of low-density polyethylene (LDPE), PP, PC and PET was studied. Due to swelling of the polymers as a result of absorption of flavour compounds, LDPE and PP showed a significant increase of oxygen permeability of 21% and 130%. The oxygen permeability of PC showed a significant decrease of 11% due to occupation or blockage of the "micro-cavities" by the absorbed flavour compounds. Flavour absorption by PET did not affect the oxygen permeability significantly.
The influence of flavour absorption LDPE, PC and PET on the taste perception of a flavour model solution and orange juice stored in glass bottles was studied with and without pieces of the respective plastic films. Although the content of flavour compounds between controls and polymer treated samples decreased substantially due to absorption, no significant effect on the taste perception of the model solution and orange juice were observed by triangular taste panel tests.
Voedingsmiddelenanalyses van de Vakgroep Humane Voeding en Epidemiologie. Deel 12 Retinol en carotenoiden in zuivelproducten
Hulshof, P.J.H. ; Roekel, T. van; Bovenkamp, P. van de; West, C.E. ; Katan, M.B. - \ 2001
voedingsmiddelen - chemische samenstelling - vetten - oliën - bakoliën - bakvetten - boter - margarine - voedingswaarde - voedsel - voedselsamenstelling - kwaliteit - eigenschappen - huishoudens - ziekenhuizen - ziekenhuiscatering - verpleeghuizen - dierlijke producten - ingrediënten - ghana - filippijnen - spijsoliën - spijsvetten - institutionele huishoudens - foods - chemical composition - fats - oils - cooking oils - cooking fats - butter - margarine - nutritive value - food - food composition - quality - properties - households - hospitals - hospital catering - nursing homes - animal products - ingredients - ghana - philippines - edible oils - edible fats - institutional households
|Netwerken in vetten
Kloek, W. - \ 1999
Voedingsmiddelentechnologie 32 (1999)9. - ISSN 0042-7934 - p. 45 - 48.
voedselindustrie - voedseltechnologie - vetten - vetzuren - dispersie - voedselkwaliteit - food industry - food technology - fats - fatty acids - dispersion - food quality
Voedingsmiddelenanalyses van de Vakgroep Humane Voeding. Deel 12 Margarines, spijsvetten, koekjes en snacks-1996
Hulshof, P.J.H. ; Kosmeijer, T. ; Zock, P.L. ; Bovenkamp, P. van de; Katan, M.B. - \ 1998
voedingsmiddelen - voedsel - chemische samenstelling - bakoliën - bakvetten - oliën - boter - margarine - voedingswaarde - voedselsamenstelling - kwaliteit - eigenschappen - huishoudens - ziekenhuizen - vetten - ziekenhuiscatering - verpleeghuizen - ingrediënten - dierlijke producten - ghana - filippijnen - spijsoliën - spijsvetten - institutionele huishoudens - foods - food - chemical composition - cooking oils - cooking fats - oils - butter - margarine - nutritive value - food composition - quality - properties - households - hospitals - fats - hospital catering - nursing homes - ingredients - animal products - ghana - philippines - edible oils - edible fats - institutional households
Daling transvetzuren, maar niet in alle grootverbruikproducten: vetzuursamenstelling van spijsvetten, koek en snacks.
Hulshof, P.J.M. ; Zock, P.L. ; Kosmeijer-Schuil, J.G. ; Bovenkamp, P. van de; Katan, M.B. - \ 1998
Voeding 59 (1998)5. - ISSN 0042-7926 - p. 24 - 27.
vetzuren - carbonzuren - vetten - oliën - bakoliën - bakvetten - zoetwaren - biscuits - fabricage - cakes - snacks - maaltijden - voedingsmiddelen - chemische samenstelling - voeding - oleïnezuur - onverzadigde vetzuren - acrylzuur - volksgezondheid - gezondheidszorg - spijsoliën - spijsvetten - fatty acids - carboxylic acids - fats - oils - cooking oils - cooking fats - confectionery - biscuits - manufacture - cakes - snacks - meals - foods - chemical composition - nutrition - oleic acid - unsaturated fatty acids - acrylic acid - public health - health care - edible oils - edible fats
Deze vetzuren hebben een ongunstige invloed op het lipoproteineprofiel in het bloed. In een tabel is de vetzuursamenstelling van geselecteerde koek en snacks weergegeven. Tegenwoordig bevatten de margarines, bak- en braadvetten aanzienlijk minder verzadigd vet
Interactive effects between dietary fat and a vegetables-fruit mixture on colorectal carcinogenesis
Rijnkels, J.M. - \ 1998
Agricultural University. Promotor(en): J.H. Koeman; G.M. Alink; R.A. Woutersen. - S.l. : Rijnkels - ISBN 9789054858171 - 128
darmziekten - maagdarmziekten - carcinoom - neoplasma's - voedsel - voedingsmiddelen - vetten - groenten - fruitgewassen - intestinal diseases - gastrointestinal diseases - carcinoma - neoplasms - food - foods - fats - vegetables - fruit crops
Several dietary compounds are associated with colorectal cancer risk. These include the amount of dietary fat, which is positively associated with colorectal cancer, and a variety of vegetables and fruit, which are suggested to possess anticarcinogenic potential. Because diet is complex and dietary factors most probably interact, it is likely that these interactive effects between dietary components, rather then the effects of individual components, may account for a large part in the risk for developing colorectal cancer.
The results of the studies performed by Alink et al. (1993) demonstrated that it is of paramount importance to study interactive effects between dietary components in evaluating the effects of total diet in colorectal carcinogenesis. They showed that the effects of a vegetables-fruit mixture on DMH-induced colorectal carcinogenesis in rats maintained on complete human diets, was modulated by the presence of other dietary components, such as the amount of dietary fat or fried meat.
To investigate these observations by Alink et al. in more detail, we performed three long-term animal studies, which have been described in detail in Part I of the present thesis. In these studies, interactive effects between dietary fat (20 and 40 energy%) and a vegetables-fruit mixture (19.5% wt/wt) were studied on 1,2-dimethylhydrazine (DMH)- and N-methyl-N'-nitro-N-nitroso-guanidine (MNNG)-induced colorectal carcinogenesis in rats, and in ApcMin mice, which are genetic susceptible for developing multiple intestinal neoplasia (Chapters 1, 2, and 3). The composition and amount of fat (40e%) and of the vegetables-fruit mixture were based on regular amounts consumed in The Netherlands.
The animal diets used for these studies were balanced for protein and micronutrient content. The diets differed only in the amount of fat/carbohydrate and the presence of specific plant constituents when a vegetables-fruit mixture was included in the diets. Notwithstanding the use of the same experimental diets in all three studies, the results were remarkably different.
A vegetables-fruit mixture added to high-fat (40e%) diets resulted in a distinct protection of colorectal carcinogenesis in the MNNG-study, whereas in the DMH study no effect of the vegetables-fruit mixture was observed. In ApcMin mice the vegetables-fruit mixture enhanced rather then inhibited tumor development. Furthermore, a diet high in fat (40e%) enhanced colorectal carcinogenesis in the DMH-study and, although less pronounced, in the MNNG-study, whereas in the ApcMin mice no effect was observed.
Finally, a vegetables-fruit mixture added to low-fat diets did not result in protection against colorectal cancer development in the MNNG-study, whereas when added to a high-fat diet an inhibitory effect was found. In male ApcMin mice, the same mixture added to low-fat diets decreased the number of small intestinal tumors, whereas it increased the number of small intestinal neoplasia when added to high-fat diets.
To examine the differences observed between the effects of the vegetables-fruit mixture observed in the DMH-model and those in the MNNG-model in more detail, an experiment was designed, in which the inhibitory potency of a vegetables-fruit mixture was investigated on either the initiation or the promotion phase, using azoxymethane (AOM) to induce colorectal carcinogenesis and using both low- and high-fat diets (Chapter 4). In this study no protection of this mixture on colorectal carcinogenesis was observed either when present during the initiation or during the promotion phase, irrespective of the fat content.
In conclusion, the variation in the results of the aforementioned studies can most probably be ascribed to methodological differences, such as differences in DMH and MNNG metabolism, route of administration and type of DNA damage. Apart from these differences, genetic susceptibility may play a role. Taken these methodological differences into account the present results do not consistently show that dietary fat has modulated the tumor preventive properties of a vegetables-fruit mixture in colorectal carcinogenesis (Alink et al., 1993).
The second part of the thesis describes the results of studies into the interactive effects between dietary fat and the vegetables-fruit mixture on (anti)carcinogenic mechanisms. Hepatic xenobiotic enzyme activities (ethoxyresorufine-O-deethylation (EROD), pentoxyresorufine-O-deethylation (PROD), N-nitrosodimethylamine-demethylase (NDMA-d), cytosolic glutathion-S-transferase (GST), UDP-glucuronyl transferase (UDP-GT)) and immune parameters in spleen and mesenteric lymph nodes (NK cell activity, lymphocyte stimulation test, mixed lymphocyte reaction) were measured in rats of the long-term DMH-study (Chapter 5).
Overall, it was shown that both a vegetables-fruit mixture and dietary fat had no effect on the enzyme activities and immune function. In a short-term (seven weeks) animal study, DMH-treatment appeared to influence hepatic and colonic xenobiotic enzyme activities (EROD, PROD, NDMA-d, UDP-GT and GST) rather strongly (Chapter 6).
Furthermore, interaction between dietary fat and the vegetables-fruit mixture was observed on colonic NDMA-d activity. Finally, interactive effects between stearic acid, indole-3-carbinol and crude extracts of the vegetables-fruit mixture were studied in vitro (Chapter 7). Both indole-3-carbinol, an isolated plant constituent, and vegetables-fruit extracts, a complex mixtures of plant constituents, modulated the effects of stearic acid on cytotoxicity, gap junctional intercellular communication, and cytochrome P450-IA (EROD) activity. The effects of indole-3-carbinol and extracts of the vegetables-fruit mixture were partly influenced by the order at which these components with stearic acid were added to the cells as well as by the type of cells used.
In general, the results of the studies described in Part II of this thesis supports the hypothesis that interaction between dietary constituents may influence their modulating effect on colorectal carcinogenesis.
Maiskolvensilage als vetverlager
Boxem, Tj. ; Zonderland, J. - \ 1996
Praktijkonderzoek Rundvee, Schapen en Paarden. Praktijkonderzoek 9 (1996)6. - ISSN 1386-8470 - p. 6 - 9.
concentraten - melkvee - melkveehouderij - verteerbaarheid - droge stof - vetten - voer - maïskuilvoer - kuilvoer - voedergrassen - concentrates - dairy cattle - dairy farming - digestibility - dry matter - fats - feeds - maize silage - silage - fodder grasses
Indien er werkelijk sprake is van een overschot aan grond en deze is er geschikt voor, dan zou de teelt van maoskolvensilage (MKS) een goede mogelijkheid kunnen bieden.
|Voedingsgewoonten van overvloed en onbehagen.
Hartog, A.P. den - \ 1996
Voeding 57 (1996)11. - ISSN 0042-7926 - p. 6 - 9.
consumentengedrag - consumptiepatronen - bakvetten - bakoliën - vetten - voedsel - voedselhygiëne - voedselinkoop - voedingsmiddelen - geschiedenis - voedingstoestand - oliën - prijzen - inkopen - sociale klassen - zoetstoffen - spijsvetten - spijsoliën - consumer behaviour - consumption patterns - cooking fats - cooking oils - fats - food - food hygiene - food purchasing - foods - history - nutritional state - oils - prices - purchasing - social classes - sweeteners - edible fats - edible oils
Vijf artikelen waarin de volgende aspecten zijn belicht: -) vijftig jaar eten in Nederland; -) sociale klasseverschillen in (op)voeding; -) voedingsaankopen in het gezin; -) invloed sociale omgeving; -) effectiviteit van vet- en suikervervangers
Interaction between carbohydrates and fat in pigs : impact on energy evaluation of feeds
Bakker, G.C.M. - \ 1996
Agricultural University. Promotor(en): M.W.A. Verstegen; A.W. Jongbloed. - S.l. : Bakker - 193
voer - voedingswaarde - koolhydraten - vetten - varkens - feeds - nutritive value - carbohydrates - fats - pigs
In marketing pigs, nearly 50% of the costs are those of the feed. Therefore, it is necessary to know the nutritional value as accurately as possible.
In the Netherlands, pigs receive in general (99%) compound feeds, containing all the nutrients they require. Cereals used to be the major ingredients. However, their proportion was reduced from 40% in 1970 to 15% in the eighties. The use of ingredients other than cereals or tapioca in compound feeds affected the chemical composition of the pig diet: from feeds with a large amount of starch towards feeds containing less starch but more fibrous polysaccharides, that are often called non-starch polysaccharides (NSP). Starch and NSP differ in many aspects: in chemical structure; in the type of nutrients they supply and their effect on other nutrients in the digestion process; efficiency of utilization for energy gain; and other, non-nutritional, aspects.
In order to have maximum benefit of their potential nutrient supply, most nutrients need to be digested and absorbed before reaching the terminal ileum. These nutrients are: amino acids from protein, fatty acids from lipids, and glucose from starch and sugars. If they disappear from the large intestine, the energy value of the nutrients will be lower, resulting in a reduced feeding value of the total feed. On the other hand, NSP are fermented mainly in the hindgut, supplying energy to the pig in the form of volatile fatty acids.
In general, the energy of pig feeds is evaluated by considering the differential contribution of digestible nutrients to energy supply. Energy evaluation is based on three assumptions: (1) that both the chemical composition and the digestibility coefficients of ingredients in a feed are known and can be derived from feedstuff tables; (2) that the amounts of digestible nutrients in the different ingredients are additive and that there are no interactions between ingredients; and (3) that after digestion the contribution of each nutrient to energy supply is independent of the amounts of other nutrients. Because NSP have a relatively low energy density, they are often supplemented with fat to maintain a certain energy density in the diet. Hence it is assumed that the feeding values are additive. It was found, however, that the combination of NSP rich by-products and fat resulted in less energy gain in pigs than an iso-energetic combination of cereals and fat or by-products separately. It was concluded that the NSP and fat interacted on energy supply to the pigs.
It is important to know whether the interactive effect between fat and fermentable carbohydrates takes place prior to the terminal ileum or in the hindgut of the pig. To be able to measure this, a new technique of ileo-cecal cannulation was developed: the steered ileo-cecal valve (SICV). In contrast to other techniques, in this technique the gut remains intact. After testing it with high fibrous diets, it was concluded that both ileal and total tract digestibility can be measured in the same pig. For this, the use of a marker is recommended.
To investigate the interaction between NSP and fat, an experiment was performed with 12 diets, in a 4 x 3 factorial arrangement with four amounts of animal fat and three sources of carbohydrate. The amounts of animal fat added to the diets were : 0 (o), 35 (1), 70 (m) and 105 (h) g per kg. The three sources of carbohydrate were maize starch (M), purified cellulose (C) and toasted soya bean hulls (S). The cellulose was. used as a source of poorly fermentable carbohydrate and the soya bean hulls as a source of easily fermentable carbohydrate. These diets were given to pen-housed pigs from 30 to 105 kg live weight, which period is the growing-finishing period in practice. In these pigs both digestibility of the diets and the energy gain were measured. In a separate set of pigs, the digestibility of nutrients at the terminal ileum was measured.
All the measured digestibility coefficients were lower than expected from the feedstuff table. This effect was partly attributed to differences in techniques for estimating digestibility between the present experiment (practical conditions) and the experiments supplying data for the feedstuff table. Most of the tabulated values are obtained under well-controlled laboratory conditions. It was found that housing pigs in groups in pens, as in common practice, reduced the digestibility of organic matter with 1.5 %-units, compared to pigs housed in metabolism crates. For protein this difference was larger: on average 3.7 %-units. Feeding high fibrous diets tended to increase these differences.
In addition, the assumption of additivity of digestible nutrients in ingredients within a diet was not correct, especially when high fibrous ingredients were used. When cellulose or soya bean hulls were included in the diet, digestibility of protein and fat was worse. It was concluded that intake of dry matter or fibrous material increased endogenous secreted protein with 36.5 g/d per kg NSP consumed, which reduced apparent digestibility. In addition, microbial protein synthesis of 116.6 g/d per kg fermented NSP also reduced apparent protein digestibility. Moreover, the added fat was less digestible at the terminal ileum when combined with cellulose or soya bean hulls in a diet, than when they were all fed separately. The total tract digestibility of the added fat was 91 % with the low fibre diet, but 83% when combined with cellulose and 87% when combined with soya bean hulls.
The energy gain predicted from the measured digestible nutrients was compared with the net energy gain as actually achieved. It was concluded that the utilization of energy from fermentable carbohydrates was relatively low: 0.43. This was partly ascribed to energy losses in methane and energy losses in volatile fatty acids in faeces. Of the digestible energy from fermentable carbohydrates 0.81 to 0.90 was available for energy gain in the form of volatile fatty acids. In addition, increased weight of the empty gastrointestinal tract was found, which may have required a large part of the available energy for maintenance, leaving less energy for growth.
It is concluded, that digestibility of nutrients should be measured both at the terminal ileum as over the total tract, when large amounts of fermentable carbohydrates are included in the diet. They should be measured under practical conditions. The variation in energy gain between pigs, however, remains relatively large.
Viscosity of dietary fibre in relation to lipid digestibility in broiler chickens
Smits, C.H.M. - \ 1996
Agricultural University. Promotor(en): M.W.A. Verstegen; A.C. Beynen. - S.l. : Smits - ISBN 9789054856085 - 140
voer - cellulose - vleeskuikens - metabolisme - lipiden - vetten - feeds - cellulose - broilers - metabolism - lipids - fats
The aim of the thesis was to identify the physicochemical properties of nonstarch polysaccharides (NSPs) that are most relevant to the nutrition of the broiler chicken. More specifically, the mechanisms by which fibre viscosity can affect lipid digestibility in broiler chickens have been investigated in a series of experiments. The effect of fibre viscosity per se was investigated by using carboxymethylcelluloses (CMC) with varying viscosity. The CMC types were non-fermentable in vitro . Fibre viscosity per se depressed the digestibility of lipids, protein and starch in broiler chickens fed diets containing CMC with varying viscosity. The effect of fibre viscosity on lipid digestibility was dependent on the type of fat. The digestibility of animal fat that was predominantly composed of saturated long chain fatty acids was depressed, whereas there was no effect on the digestibility of soyabean oil or coconut oil. The reduction in lipid digestibility coincided with a reduced bile salt concentration and raised microbial numbers in the small intestine. CMC did not affect the condition of the small intestinal mucosa. The morphological parameters indicated that the condition of the mucosa was even improved in CMC fed birds. A study with germfree rats and rats with a specific pathogen free intestinal flora revealed that the effect of CMC on lipid digestibility is mediated, at least partially, by the intestinal flora. it was concluded that the small intestinal microflora can mediate the antinutritive effect of fibre viscosity on lipid digestibility in broiler chickens. Moreover, it was proposed that a reduction in bile salt concentration and bacterial transformation of bile salts reduces their efficacy to solubilise lipids. The results show that fibre viscosity is an important antinutritive property which should be taken into account in diet formulation for broiler chickens.