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1
Koo, Malcolm M. O. "Dietary fibre, dietary fat, and menarche." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0016/NQ53669.pdf.
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Sels, Jean-Pierre Joseph Emile. "Dietary fibre and diabetes mellitus." Maastricht : Maastricht : Datawyse ; University Library, Maastricht University [Host], 1991. http://arno.unimaas.nl/show.cgi?fid=5618.
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Svanberg, Maria. "Effects of processing on dietary fibre in vegetables." Lund : Dept. of Applied Nutrition and Food Chemistry, Lund Institute of Technology, Lund University, 1997. http://books.google.com/books?id=EcZtAAAAMAAJ.
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Brownlee, Iain. "The interaction of dietary fibre and colonic mucus." Thesis, University of Newcastle Upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275525.
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Edwards, Sandra L. "Investigation of ispaghula husk arabinoxylan structure." Thesis, London South Bank University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271763.
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Malik, Amirmuslim, and mikewood@deakin edu au. "Studies on dietary fibre: Analysis, epidemiological and physiological aspects." Deakin University. School of Sciences, 1986. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20050902.142103.
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This thesis involves an investigation in three areas; first, a study of an enzymatic-gravimetric method for the analysis of dietary fibre; second, a survey of dietary fibre intake in an area of a developing country, and finally, some observations on the functional aspects of gel-forming dietary fibre in the rat.
A simple and rapid enzymatic-gravimetric assay for both soluble and insoluble dietary fibre has been critically investigated. Reference samples were also analysed by a more comprehensive, enzymatic gas chromatographic method to allow testing of the relative accuracy of the enzymatic-gravimetric method. The enzymatic-gravimetric method was found to be highly reproducible but gave a slightly higher value for total dietary fibre than the more comprehensive method. This discrepancy is probably due to the presence of small quantities of resistant starch and protein residue which are recovered in the enzymatic-gravimetric method. In the enzymatic-gas chromatographic method, protein residue is not measured, and resistant starch is estimated, but not counted as dietary fibre.
The enzymatic-gravimetric method was applied to the analysis of foods commonly consumed in the Padang region of West Sumatra in Indonesia, in order to estimate dietary fibre intake in the region. Daily intakes of usual foods were estimated by use of a 24-hour recall procedure aided by food photographs to assist in the estimation of portion size. Samples of approximately 60 of the most commonly consumed foods were collected and analysed for dietary fibre. These appear to be the first data which report values for dietary fibre in Indonesion foods and they represent a significant
improvement upon the existing data on crude fibre content. Knowledge of the amounts of foods usually consumed and their dietary fibre content allowed an estimation of usual intakes of dietary fibre. Fibre intake was found to be lower than in the developing countries of Africa and was comparable to intakes measured in the U.K. This is the first study to show that in this part of South East Asia, a developing country area using polished rice as a staple food, dietary fibre intakes are as low as in Western countries.
Low intakes of fibre are believed to be related to the prevalence of a range of diseases and, in this study, preliminary data on the rates of non-infective, chronic diseases were collected from the two main hospitals in West Sumatra. Chronic, non-infectious diseases such as inguinal hernia, appendicitis, haemorrhoids, diabetes mellitus, hypertension and malignant neoplasms of the rectum are relatively frequent in West Sumatra. While no firm conclusions can be drawn from these data, they do show the possibility of a relationship between low intakes of dietary fibre and the prevalence of these diseases, and suggest that further investigation is necessary.
Some observations were made of the effect of gel-forming dietary fibre on stomach emptying and intestinal transit rate in the rat. Xanthan gum was added to iso-osmotic solutions to produce increased viscosity and phenol sulphonphthalein (phenol red) was used as a non-absorbable marker. Gavage feeding of solutions with a range of viscosities was used to study the effect of viscosity on the rate of stomach emptying and intestinal transit. Increased viscosity was observed to slow gastro-intestinal transit and this provides one mechanism by which dietary fibre of the gel-forming type ray improve glucose tolerance.
7
Coleman, Leana. "Dietary fat and fibre alters colon risk in the rat /." Title page and abstract only, 1999. http://web4.library.adelaide.edu.au/theses/09SB/09sbc692.pdf.
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Burley, Victoria Jane. "The effects of dietary fibre on energy intake and appetite." Thesis, King's College London (University of London), 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295734.
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Shahjalal, Md. "Partition of dietary energy and protein between fibre and other body components in fibre producing goats." Thesis, University of Aberdeen, 1991. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU548061.
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The relationship between dietary nutrient inputs, particularly energy and protein, and their partition between fibre, meat and other non-meat components in British fibre producing goats was studied in a series of four experiments. Experiment 1 indicated that increasing dietary energy concentration from 10.2 to 11.9 MJ ME/kg dry matter (DM) significantly (P &'60 0.05 to 0.001) improved liveweight gain, feed conversion efficiency, carcass weight, cross sectional area of M.longissimus dorsi , and increased fat thickness over N.serratus dorsalis . Values were also increased in the carcass for dissected lean tissue and crude protein, weights and proportions of dissected and chemically extractable fat, weights of liver, kidneys and also fat deposition in the omental and perirenal plus retro-peritoneal depots. No consistent effects due to dietary energy inputs were observed for yield and diameter of mohair fibres. Similarly, changing the dietary protein concentration from 108 to 180 g/kg DM resulted in significantly (P &'60 0.05 to P &'60 0.001) increased values for live weight gain, DM intake, feed conversion efficiency, carcass weight, killing out proportions, area, width and depth of M.longissimus dorsi , weights of dissected carcass lean tissue, chemically determined crude protein and lipid in the carcass and also greater yield and diameter of mohair fibres. The results of experiment 2 indicated that increasing dietary protein concentrations (102, 126, 165, 185 g/kg DM) by the inclusion of fish and soya bean meal increased (linear effect, P &'60 0.05 to P &'60 0.001) live weight gain, feed conversion efficiency, carcass weight, width of M.longissimus dorsi , weight and proportion of dissectible carcass lean tissue and weight of crude protein in the carcass, liver and kidneys. The clean fibre yield and diameter were increased as the dietary CP concentration increased from 102 to 165 g/kg DM and then decreased at the highest CP concentration of 185 g/kg DM. Experiment 3 showed that source of nitrogen supplementation (urea, fish meal or soya bean meal) had no significant effects on growth rate, DM intake, feed conversion efficiency and nitrogen balance. However, soya bean meal supplementation resulted in significantly (P &'60 0.05 to P &'60 0.001) higher values for nitrogen digestibility, carcass weight, killing out proportion, dissectible lean tissue with trends to increase area of M.longissimus dorsi and microbial protein synthesis. The yield and diameter of mohair fibre were increased (P &'60 0.05) due to protein supplementation compared with the NPN supplementation in the diet. Experiment 4 indicated that average growth rate, DM intake, feed conversion efficiency, carcass weight and killing out proportions were not significantly different for the source of nitrogen supplementation (urea v fish meal) or for the genotype of Cashmere goats (Russian v Australasian crosses). Mid-side fleece growth (Cashmere &'43 guard hair) was significantly (P &'60 0.05) higher in goats given fish meal rather than urea supplemented diet and Russian goats tended to produce higher proportion of cashmere in the mid-side and in total fleece samples than those of Australasian genotype.
10
Chinery, Rebecca. "Growth control mechanisms, luminal factors, and cancer : a molecular approach." Thesis, Imperial College London, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263832.
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Key, Fiona Brigit. "Digestion and large intestinal fermentation of breads and haricot beans (Phaseolus vulgaris)." Thesis, University of Newcastle Upon Tyne, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308980.
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Vlitos, Amanda. "Bowel function and non-starch polysaccharide intake during the menstrual cycle." Thesis, London South Bank University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259943.
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Nilsson, Mathias. "The dietary fibre complex of rye grain, with emphasis on arabinoxylan /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5494-8.pdf.
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Karppinen, Sirpa. "Dietary fibre components of rye bran and their fermentation in vitro /." Espoo : Technical Research Centre of Finland, 2003. http://www.vtt.fi/inf/pdf/publications/2003/P500.pdf.
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Armstrong, Elizabeth Freda. "Effects of wheat bran and pectin rich diets on colonic metabolism in the rat." Thesis, University of Edinburgh, 1989. http://hdl.handle.net/1842/23684.
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Elhardallou, Sirelkhatim Balla. "Studies on the functional properties of three starchy legumes and their fibre-rich fractions." Thesis, University of Reading, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.258373.
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Rees, Gail. "Diet, bowel function and irritable bowel syndrome." Thesis, London South Bank University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336373.
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Cameron-Smith, David, and edu au jillj@deakin edu au mikewood@deakin edu au wildol@deakin edu au kimg@deakin. "THE INTERACTION OF DIETARY FIBRE, CARBOHYDRATE METABOLISM AND DIABETES IN THE RAT." Deakin University. School of Health and Behavioral Sciences, 1994. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20040622.171657.
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It is currently accepted that the most appropriate diet in the treatment of non-insulin-dependent diabetes mellitus "eNIDDM"e
is high in carbohydrates, high in fibre and low in fat. Dietary fibre reduces the rate of carbohydrate absorption, which may have a beneficial effect on insulin action. Furthermore, high fibre diets also increase the amount of carbohydrates which are not absorbed from the small intestine. These malabsorbed carbohydrates are fermented by the bacterial population in the large intestine, producing short chain fatty acids "eSCFA"e, including propionate, which has been shown to alter liver carbohydrate metabolism. This thesis investigated the actions of slowed carbohydrate absorption and carbohydrate malabsorption in streptozotocin-induced "eSTZ"e diabetic rats.
High carbohydrate diet supplemented with guar gum, a soluble dietary fibre, fed to STZ diabetic rats improved insulin sensitivity. investigation of the alterations in the stomach and small intestine demonstrated that guar increased the viscosity of the meal in the intestine. The action of increased fermentation, producing more propionate, was investigated by supplementing propionate into the diets of STZ diabetic rats or when perfused into isolated rat livers. No changes in insulin action or liver glucose metabolism were measured. in addition, it was shown that guar gum reduces food intake in STZ diabetic rats. Mild reductions in food intake in STZ diabetic rats were shown to increase insulin action.
In summary, STZ diabetic rats fed high carbohydrate, high fibre diets reductions in food consumption and slowed carbohydrate absorption are important factors which may lower blood glucose concentrations and increase insulin action. increased SCFA production is unlikely to contribute significantly to the improvements in insulin action.
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Munian, A. C. "Pineapple dietary fibre and the effects of processing on its functional properties." Master's thesis, University of Cape Town, 2006. http://hdl.handle.net/11427/11738.
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Includes bibliographical references.The waste streams from the pineapple canning industry are a valuable source of carbohydrates, in particular dietary fibre (DF) and neutral sugars. In addition, the waste is a suitable source of antioxidants, enzymes such as bromelin and flavours. Since this waste (core and peel) is currently sold at minimal cost to cattle farmers for use as cattle feed or compost, alternative uses of the material with commercial potential was investigated.
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Jagoe, Robert Thomas. "Mechanisms and consequences of nutritional depletion in early lung cancer." Thesis, University of Newcastle Upon Tyne, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311117.
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Rumney, C. J. "An in vitro study of the metabolic activities of bacteria from the human colon." Thesis, Open University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234270.
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Brennan, Margaret Anne. "Modulating the glycaemic response of ready to eat extruded snack products utilising dietary fibre and fibre rich waste stream materials." Thesis, Manchester Metropolitan University, 2012. http://e-space.mmu.ac.uk/313188/.
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The aim of this Ph.D. was to utilise commercial dietary fibre (DF) sources as well as DF from food waste streams to create snacks capable of reducing glycaemic response (GR). Obesity is a rising global epidemic due to changes in lifestyle, eating and exercise habits. Consumer demand for convenience has led to greater consumption of highly processed and refined foods so that even though cereal consumption is still high, many of the associated phytochemicals are removed, creating snacks high in energy and low in DF. High energy, low DF, diets have been linked to diabetes, certain types of cancer and heart disease. Health conscious consumers are demanding ‘healthy’ snack foods. In phase one DF rich products (at 5, 10 and 15 % w/w wheat flour replacement levels; total of 23 different samples) were incorporated into extruded snacks to determine the role of DFs in altering their physicochemical and nutritional characteristics. Starch digestion was shown to be lowered with all of high DF snacks (P ≤ 0.05), however, this was not always dose responsive (oat bran and super gum showed no difference with increasing concentrations). Product texture and viscosity parameters were also affected by DF although no general pattern could be observed. In phase two oat bran and psyllium material were incorporated into snack foods at 15 % (w/w) to evaluate potential GR in vitro and also in vivo (intervention study of 12 healthy subjects aged 18-40 yrs, with BMI 22.5-28, a total of 184 finger prick samples). Psyllium extruded snacks achieved attenuated in vitro and in vivo GR, (P ≤ 0.05). Oat bran reduced the in vitro but not in vivo response (P ≤ 0.05). Water absorption was negatively correlated with in vitro digestion (20 min) and in vivo AUC (P ≤ 0.05). In conclusion, the findings from this Ph. D. indicate the mechanism of DF ability to attenuate GR is related to its ability to bind water, and not all DFs behave in a similar fashion. Further research is required to elucidate the role of water in starch digestion and the impact on GR.
23
Andersson, Annica. "Characterisation of barley and barley fractions, with emphasis on dietary fibre and starch /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5748-3.pdf.
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Harris, Suzanne. "Exploring the relationship between the structure of wheat dietary fibre and prebiotic activity." Thesis, University of Reading, 2018. http://centaur.reading.ac.uk/78863/.
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The relationships between wheat dietary fibre (DF) and prebiotic effects were investigated by testing how various DF types in different combinations and how the structure, of the major DF component of wheat, arabinoxylan (AX) modulate prebiotic activity. It was hypothesised that DFs could act synergistically resulting in different prebiotic activities when fermented in vitro at different ratios. The DF, arabinogalactan-peptide (AGP) was isolated from wheat flour and characterised, AX and mixed-linked β-glucan were commercially bought. The three fractions were tested singly and in combination in in vitro fermentation studies to assess their prebiotic activity when used individually and in different combinations. SCFAs produced from in vitro fermentation were measured using HPLC; flow-FISH was used for bacterial enumeration. Increases in bifidobacteria and acetate were observed with combinations of AGP and AX fractions. There were no additive effects on prebiotic activity when AGP and AX were combined; the greatest increases in total SCFAs, bifidobacteria and total bacteria were observed when AX and β-glucan were combined at a 3:1 ratio. The importance of AX structure was investigated using AX isolated from transgenic wheat with an altered arabinosylation pattern and pre-incubation of AX fractions in a simulated gastric digest prior to in vitro colonic fermentation. AX isolated from flour of homozygous TaXAT1 RNAi transgenic wheat showed lower prebiotic activity compared to AX isolated from flour of the corresponding azygous control wheat. Pre-incubation of AX in an in vitro gastric digest resulted in smaller AXOS, a lower A:X ratio, improved bacterial composition and slower fermentation compared to the control. Based on these results, three soluble arabinoxylan (AX) fractions from wheat flour with different average molecular mass (MM) and one insoluble AX fraction were subjected to in vitro gastric and duodenal digestion prior to in vitro fermentation, resulting in an increase in smaller AXOS, decreases in MM, viscosity and A:X ratio and a reduction in bound ferulic acid. Differences in prebiotic activity were observed between AX samples of different MM after changes in structure caused by in vitro digestion. The AX fraction of 323kDa gave the greatest increases in SCFA production, while the insoluble AX fraction showed the smallest increases in SCFA production.
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Aldwairji, Maryam A. O. D. "The association between dietary fibre intakes and incidence of type 2 diabetes mellitus." Thesis, University of Leeds, 2013. http://etheses.whiterose.ac.uk/6334/.
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The incidence of diabetes is increasing alarmingly indicating a need for preventive strategies. Prospective evidence is inconclusive regarding the protective effect of high fibre intake on the risk of Type 2 diabetes mellitus (T2DM). Differences in fibre measuring methodologies may have contributed some of these inconsistencies. For the first time, this thesis employed both laboratory and epidemiological approaches to explore different aspects of dietary fibre. Firstly, 14 commonly consumed legumes were analysed for fibre content using the Association of Official Analytical Chemists (AOAC) method, and the values were significantly higher than published non-starch polysaccharide (NSP) values, with a mean AOAC-fibre: NSP ratio of 1:1.43. The UK Women’s Cohort Study (UKWCS) data was used to compare AOAC-fibre intakes with NSP intakes. Good agreement (Kappa = 0.9) was observed between intakes of AOAC-fibre and NSP with a resulting AOAC-fibre: NSP ratio being generated of 1:1.43. Following this, the links between risk of incident T2DM and intakes of AOAC-fibre and NSP were investigated. There was no evidence of dose-response relationships between T2DM risk and total fibre intake (AOAC-fibre and NSP) or from key fibre sources, except an age-adjusted lower risk of T2DM with every 5g/day increment in cereal fibre (OR=0.86; 95%CI: 0.75, 0.99). As an important fibre provider; the relationship between the risk of T2DM and legume consumption was also explored. Women in the highest dried legumes intake category experienced significantly lower odds of incident T2DM (OR=0.85; 95%:0.52, 0.89, p =0.03) compared to women in the lowest category. Agreement of fibre intake obtained using different dietary assessments approaches suggested fair agreement of diary derived NSP vs. FFQ derived NSP and poor agreement for vegetable fibre. Overall, results do not support an increase in fibre intake to prevent diabetes in the studied population, although there may be a benefit of increased dried legume intake.
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Durmic, Zorica. "Evaluation of dietary fibre as contributing factor in the development of swine dysentery." Thesis, Durmic, Zorica (2000) Evaluation of dietary fibre as contributing factor in the development of swine dysentery. PhD thesis, Murdoch University, 2000. https://researchrepository.murdoch.edu.au/id/eprint/53542/.
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Diets that alter fermentation in the hindgut of pigs have been shown to influence the incidence of swine dysentery (SD), an infectious mucohaemorrhagic colitis in pigs caused by infection with the bacterium Serpulina hyodysenteriae. Reducing fermentation can help protect pigs from developing the disease, whilst the fully protective diet, based on cooked white rice, has been described. The aim of this study was to determine links between the diet fed to pigs, hindgut fermentation, and the incidence of SD, and then to develop a commercially applicable diet that would protect pigs against SD.
In this study, the first procedure was to estimate pig performance and the hindgut fermentation that occurred when pigs were fed different diets. This was followed by infection trials to provide information on the incidence of SD when these diets were fed. These results were brought together to provide the required information. Overall 246 weaner pigs were fed one of 20 diets in six experiments. Diets were formulated either to investigate the role of different types and levels of dietary fibre on susceptibility to SD, or to test some dietary treatments (dietary extrusion, addition of exogenous enzymes, application of a protective diet after experimental infection) designed to help prevent or reduce the expression of SD. All pigs were fed the experimental diets for four to eight weeks, and then half of the pigs on each diet were killed and their large intestines collected to assess hindgut fermentation. The remaining pigs on each diet were infected with a virulent strain of S. hyodysenteriae and monitored for SD.
Hindgut fermentation was suppressed in pigs consuming diets with low levels of fermentable fibre (resistant starch, RS, and soluble non-starch polysaccharides, sNSP), and these pigs did not develop SD. The dietary inclusion of either RS, sNSP, or both to an otherwise protective diet based on cooked rice, resulted in increased hindgut fermentation and a high incidence (80 - 100%) of iv SD. Extrusion of wheat reduced hindgut fermentation and the incidence of disease in experimentally infected pigs in one experiment, but not in the other. Dietary addition of an sNSP-degrading enzyme reduced hindgut fermentation and the incidence of SD only when added to a raw wheat diet, or when combined with an RS-degrading enzyme in an extruded wheat diet. Finely ground sorghum-based diets caused a substantial decrease in fermentation, also achieving a considerable reduction in the disease. Further extrusion and/or addition of RS-degrading enzymes did not improve this effect.
The present study confirmed that diets varying in their RS and sNSP content affect several events in the large intestine, with diets having low levels of these ingredients having a capacity to reduce the incidence of SD. This study however failed to identify a diet which would be fully protective as well as commercially applicable and financially viable in farmed pig production. Although protection against SD in pigs by dietary treatments was imperfect, some of these treatments might still be useful if undertaken in combination with other methods for the prevention and control of SD.
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Lee, Richard Philip. "Setting science-based international food standards : defining dietary fibre in the Codex Alimentarius Commission." Thesis, University of Newcastle Upon Tyne, 2010. http://hdl.handle.net/10443/1644.
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The thesis presents a sociological analysis of international food standard-setting in the Codex Alimentarius Commission (the Codex). The Codex is an intergovernmental organisation jointly administered by the UN Food and Agricultural Organisation and the World Health Organisation. The main activity of member governments who participate in the Codex is the negotiation of international food standards, which are referenced by W orId Trade Organisation agreements. Although international food standards are significant instruments which structure the agri-food system, little social science research has been conducted on the process by which such standards are set. In order to develop an in-depth analysis of the science-based standard-setting process, the thesis analyses a case-study of the attempt to agree a definition of dietary fibre within the Codex. Agreeing a definition of dietary fibre was a protracted and contentious process within the Codex, with important implications for food product development and the creation of new markets. Methods used in the study included: observations of meetings, document analysis and thirty-two interviews with scientists, government delegates and food industry and consumer representatives. In this case-study, the concept of epistemic communities - defined by Haas (1992a: 3) as " ... a network of professionals with recognised expertise and competence in a particular domain and an authoritative claim to policy-relevant knowledge within the domain or issue-area" - was deemed to provide a weak explanation for the standard-setting process due to a failure to address the conditions giving rise to particular knowledge claims. Instead - and following critiques developed within the sociology of science and technology - the analysis suggests that international food standard-setting uses scientific knowledge claims, but cannot be said to be wholly based upon science because of the constitutive entanglement of science and politics. The thesis argues that the production of a definition for dietary fibre followed a methodology of standard-setting that required dietary fibre to became a 'boundary object' (Star and Griesemer, 1989) - an identifiable object around which conflicting groups can co-operate because the object possesses just enough ambiguity to allow for multiple interpretations. The thesis concludes that, in this case-study, on-going scientific controversy does not prevent the agreement of a food standard - despite food standards being 'science-based' - if the standard in question can be negotiated as a boundary object. The thesis provides novel social scientific insights into a little studied, but increasingly significant, area of the agri-food system.
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Radwan, Mokhtar Sayed. "Nutritional studies on rabbits and rats with special reference to sources of dietary fibre." Thesis, Cardiff University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314765.
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Threapleton, Diane Erin. "Cardiovascular disease risk and dietary fibre intake in the United Kingdom Women's Cohort Study." Thesis, University of Leeds, 2014. http://etheses.whiterose.ac.uk/6423/.
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Background: Dietary fibre has been associated with risk of cardiovascular disease (CVD) in some cohort studies around the world. Key health messages may be created by examining the types or sources of fibre in the diet and associated risk of different CVD events but few studies have explored this. Methods: I conducted a systematic literature review of published studies investigating dietary fibre intake and CVD. Associations were explored using dose-response meta-analysis in addition to potential non-linear associations. CVD event data for the UK Women’s Cohort Study were obtained from death records, hospital episode statistics (HES) and the Myocardial Ischaemia National Audit Project (MINAP). Capture-recapture methods were then applied to estimate the potential for missing cases. Survival analyses for coronary heart disease (CHD), stroke and total CVD risk in association with total fibre intake and fibre from key food sources were conducted using a cohort approach for food frequency data and case-cohort methods were used for analyses with food diary data. Results: Meta-analyses broadly supported inverse associations between CVD and fibre intake. Combined data from 9 studies indicate lower CVD risk per 7g/day greater intake in total fibre, relative risk 0.91 (95% confidence intervals (CI) 0.88, 0.94). After 14 years, 821 CHD and 388 stroke cases were observed. Total fibre, soluble, insoluble and fibre from cereals assessed using FFQs were associated with lower risk of stroke. With each 6g/day higher total fibre intake, hazard ratio (HR) 0.89 (95% CI: 0.81, 0.99). Higher fibre density was associated with lower risk of myocardial infarction, for every 2g/1000kcal/day higher intake, HR 0.89 (95% CI: 0.81, 0.98). Higher cereal fibre intake, calculated using food diaries, was associated with lower risk of acute coronary events HR 0.76 (95% CI: 0.58, 1.00). Conclusion: Fibre intake is inversely associated with CVD risk in a dose response relationship after accounting for other potentially confounding influences. Associations were stronger for stroke risk, when the source of fibre was cereals and in those without hypertension.
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Le, Leu Richard Kevin. "The influence of dietary fibre from barley fraction on DMH-induced intestinal cancer in rats /." Title page and abstract only, 1993. http://web4.library.adelaide.edu.au/theses/09SB/09sbl539.pdf.
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North, Christina Johanna. "Effect of dietary fibre on selected haemostatic variables and C-reactive protein / Christina Johanna North." Thesis, North-West University, 2006. http://hdl.handle.net/10394/1417.
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Motivation: Cardiovascular heart disease (CVD) is the leading cause of death worldwide. Risk markers for CVD include, amongst others, the haemostatic factors tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor type 1 (PAI-1), factor VII (FVII) and fibrinogen and more recently, C-reactive protein (CRP), a sensitive marker of inflammation. Epidemiological studies have demonstrated an inverse association between dietary fibre (DF) consumption and risk factors for CVD and CVD prevalence. Some research indicates that this protection may be related to favourable changes in the haemostatic profile and inflammatory markers. This is applicable for the consumption of total DF, as well as soluble and insoluble fibre. However, clinical intervention trials report conflicting data on the effects of DF on t-PA, PAI-1, FVII, fibrinogen and CRP. In addition, available literature is not clear on the mechanisms through which DF may have favourable effects.
Objective: The main objective of this study was to review the results of randomised controlled trials systematically on the effects of DF on the above-mentioned selected haemostatic variables and CRP in healthy adults and subjects with hypertriglyceridaemia and the metabolic syndrome.
Methods: Human adult intervention trials, at least two weeks in duration, with an increased and measurable consumption of DF were included. Electronic databases were searched from the earliest record to May/July 2006 and supplemented by crosschecking reference lists of relevant publications. From the literature search, two reviewers identified studies that were rated for quality based on the published methodology. No formal statistical analysis was performed due to the large differences in the study designs of the dietary intervention trials. The primary outcome measures were percentage changes between intervention and control groups, or baseline to end comparisons for t-PA, PAI-1, FVII, fibrinogen and CRP.
Results t-PA activity increased significantly (14-167%) over the short and long-term following increased fibre intakes. PAI-1 activity decreased significantly between 15-57% over periods ranging from two to six weeks. These favourable changes in t-PA and PAI-1 occurred in healthy, hypertriglyceridaemic and metabolic syndrome subjects following consumption of diets containing ≥3.3 g/MJ DF and ≥4.5 g/MJ DF respectively.
Mechanisms through which DF may affect t-PA and PAI-1 include its lowering effect on insulinaemic and glycaemic responses, decreasing triglycerides which are a precursor of very-low-density lipoproteins, fermentation of DF to short-chain fatty acids, which may reduce free fatty acid concentrations, as well as the role of DF in promoting weight loss.
High DF intakes did not have a significant effect on fibrinogen concentrations possibly because of relatively little weight loss, too low DF dosages and maintaining a good nutritional status. Inadequate study designs deterred from meaningful conclusions.
Significant decreases in FVll coagulant activity (6-16%) were observed with DF intakes
of ≥3.3 g/MJ and concomitant decreased saturated fat intakes and weight loss in
healthy and hypertriglyceridaemic subjects. Confounding factors include weight loss
and a simultaneous decreased intake of saturated fats. The type of fibre seems to play
a role as well. Mechanisms through which DF may reduce FVll concentrations include
its effects on triglyceride-rich lipoproteins, insulin and weight loss.
Increased DF consumption with dosages ranging between 3.3-7.8 g/MJ were followed by significantly lower CRP concentrations (25-54%), however, simultaneous weight loss and altered fatty acid intakes were also present in all the studies. Mechanisms are inconclusive but may involve the effect of DF on weight loss, insulin, glucose, adiponectin, interleukin-6, free fatty acids and triglycerides. Conclusions: Epidemiological evidence indicates an association between DF and the CVD risk factors t-PA, PAI-1, FVII, fibrinogen and CRP. In general, the risk of CVD may improve with high-fibre intakes as indicated by the favourable changes in some of the parameters.
However, simultaneous reduced fat intakes and weight loss presented difficulties in separating out the effects of specific components. Furthermore, DF is consumed in a variety of different forms and different dosages that may have different effects. Overall, the study designs used in the intervention trials prevented significant conclusions. DF did, however, play a role in modifying t-PA, PAI-1, FVII and CRP. Potential effects on fibrinogen were not quantifiable.
Recommendations: The results from this investigation provide the motivation for additional controlled clinical research to establish the effect and mechanisms of DF on haemostatic variables and CRP. A critical aspect of future studies would be to set up suitable protocols. The amount of subjects, duration of the trials, confounding factors such as weight loss and altered fat intakes and differentiation between types and dosage of DF are important. DF supplemental studies are recommended as they may be the most suitable method to reach meaningful conclusions.Thesis (Ph.D. (Nutrition))--North-West University, Potchefstroom Campus, 2007
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Lewis, Stephen John. "An investigation into the mechanism by which dietary fibre protects against breast and colonic malignancy." Thesis, University of Bristol, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390140.
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Silva, Vanessa Martins da. "Estudo da secagem em leito fixo e de jorro do residuo industrial do processamento de suco de frutas citricas." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/254792.
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Orientador: Luiz Antonio ViottoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
Made available in DSpace on 2018-08-09T00:16:44Z (GMT). No. of bitstreams: 1 Silva_VanessaMartinsda_M.pdf: 890535 bytes, checksum: fd3ef6ed9e8acb75a4e9410eb1cf3094 (MD5) Previous issue date: 2007
Resumo: Este trabalho teve como objetivo estudar a secagem do resíduo sólido industrial proveniente da fabricação de suco de frutas cítricas em um equipamento de leito fixo e de jorro, com a finalidade de produzir fibra dietética, como ingrediente alimentício. Para isso, foi utilizado como matéria-prima o limão da variedade siciliano para obtenção do resíduo sólido o qual foi produzido em escala piloto por método padronizado (extratora, moinho e prensa) e armazenado a 10°C. As isotermas de dessorção do resíduo sólido foram determinadas com a finalidade de se conhecer os valores de umidade de equilíbrio, e foram obtidas através do método gravimétrico estático utilizando soluções salinas saturadas, nas temperaturas de 60, 75 e 90°C. Os dados experimentais foram ajustados a diversos modelos sendo que o modelo de GAB foi o que apresentou o melhor ajuste nesta faixa de temperatura. Para a secagem em leito fixo foi realizado um planejamento experimental fatorial completo 22 onde as variáveis independentes estudadas foram: velocidade do ar de 0,5, 0,75 e 1m/s e temperatura do ar de 60, 75 e 90°C. Os dados experimentais foram ajustados ao modelo de Fick e os valores de difusividade efetiva obtidos variaram na faixa de 4,72 a 14,6.10-10m/s2, foi ajustado também o modelo exponencial e os valores da constante de secagem variaram na faixa de 6,49 a 20,90.10-4s-1. As respostas do planejamento em relação às propriedades tecnológicas de: índice de absorção de água, índice de solubilidade em água, índice de absorção de óleo e volume de intumescimento não apresentaram diferenças significativas ao nível de significância de 5%. Para a secagem no equipamento de leito de jorro foram determinadas as curvas de secagem do resíduo com um conteúdo inicial de umidade de cerca de 40%, em base úmida, fixando-se uma vazão total de ar de 78,53m3/h, que corresponde à uma velocidade de 3,89m/s para a região do jorro e de 1,01m/s para a região do ânulo, altura de leito fixo de 15cm e temperatura do ar de secagem de 60, 75 e 90°C. Os dados experimentais obtidos no secador de leito de jorro foram ajustados ao modelo de Fick e os valores de difusividade efetiva observados variaram na faixa de 2,64 a 4,26.10-9m/s2, foi ajustado também o modelo exponencial e os valores da constante de secagem variaram na faixa de 3,5 a 5,4.10-3 s-1
Abstract: This work investigated the drying of by-products of citrus juice manufacture in a convective vertical tray dryer and spouted bed dryer with the purpose of producing dietary fiber as a food ingredient. The raw material used was lemon from the sicilian variety, which solid residue was produced in pilot scale by standardized method (extractor, mill and press) and stored at 10°C. Measurement and modeling of sorption isotherms were used to determine equilibrium moisture content. The isotherms were obtained at three different temperatures (60, 75 and 90°C) using the static method with saturated salt solutions. Experimental data was fitted by several models (BET, GAB, Henderson, Peleg and Oswin). The best fitting was obtained with GAB model. The drying in tray dryer was delineated according to a central composite experimental design (22) using as factors: air velocity (0,5, 0,75 and 1m/s) and air temperature (60, 75 and 90°C). The drying kinetics experimental data were fitted using diffusional model and the effective diffusivities values were between 4,72 and 14,6.10-10 m/s2, presenting good fit to the exponential model, and drying constant varied from 6,49 to 20,90.10-4s-1. The experimental design responses evaluated were related to fibres tecnological properties: water-holding capacity, water solubility, oil-holding capacity and swelling. According to the results, they did not show significant differences at 5% of significance level. In the spouted bed, drying curves were obtained with the material at 40% (wet base), fixing total air flow rate of 78,53 m3/h, which corresponds to an air velocity of 3,89m/s in spout region and 1,01m/s in downcomer, height of fixed bed of 15cm at 60, 75 and 90°C. The experimental data was fitted using diffusional model and the obtained effective diffusivities varied from 2,64 to 4,26.10-9m/s2 to spouted bed, showing a good fit to the exponential model, and drying constant varied in the range of 3,5 to 5,4.10-3 s-1
Mestrado
Engenharia de Alimentos
Mestre em Engenharia de Alimentos
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DE, SANTIS MICHELE. "Characterization of old and modern durum wheat genotypes in relation to gluten protein and dietary fibre composition." Doctoral thesis, Università di Foggia, 2016. http://hdl.handle.net/11369/363153.
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Old wheat varieties have been suggested to have greater health benefits compared with modern cultivars in relation to both bioactive components and gluten composition. However limited data are available supporting this hypothesis, in particular for durum wheat. So the purpose of this thesis was to improve our understanding of the influence of Italian 20th century breeding on the main grain quality characters. To this aim phenotyping of an old and a modern durum wheat group of genotypes was performed in relation to gluten and dietary fibre composition. The better gluten index observed in the modern group of genotypes was related to higher contents of glutenin and B- type LMW-GS which were, on average, two times higher in the modern group of durum wheat genotypes. Instead, a drastic reduction of the content of ω- 5 gliadins, also known as Tri a 19 a major allergen in food wheat allergy (WDEIA), was observed in the modern genotypes. The immunological and proteomic approaches adopted allowed these differences to be related not only to global down-expression, but also differences in specific isoforms.
In relation to environmental influence on gluten protein composition, a higher glia/glu ratio, and contents of omega gliadins and type B LMW-GS content were observed when water deficit occurred during grain filling in 2013 crop season.
Cell wall dietary fibre were determined with arabinoxylan (AX) and β-glucan (MLG) composition being determined by enzymatic fingerprinting in wholemeal and semolina flour.
Although no significant variations were observed in the total amount of AX, a higher proportion of water soluble AX was observed in the modern varieties in wholemeal flour.
The water soluble AX extracted from semolina flour showed a lower arabinose : xylose ratio in the old genotypes while a higher MLG content in semolina was observed in modern varieties. No differences were observed between the viscosities of aqueous extracts of soluble DF in old and recent varieties but considerable variability was observed between the different durum wheat genotypes. Similarly, no significant differences were observed between the contents of bound phenolic acids in the old and the modern genotypes.
In relation to environmental influence on dietary fibre composition, increases in %WE-AX, relative viscosity and G3/G4 β-glucan ratio were observed when higher rainfall occurred during grain filling in 2014.
In conclusion the 20th century breeding seems to have improved both technological and healthy quality of Italian durum wheat genotypes.
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Mansoorian, Bahareh. "Effect of food matrix interaction between dietary fibre and polyphenols on their metabolism by colonic bacteria." Thesis, University of Glasgow, 2014. http://theses.gla.ac.uk/6136/.
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Background: The consumption of plant based foods has demonstrated an inverse association with disease prevalence. Among the components of plant based foods, polyphenol and fibre are two of the main contenders for many health benefits. The majority of polyphenols and fibre pass through the small intestine unabsorbed, reaching the colon where they are subjected to the action of the colonic microbiota; resulting in the production of the potentially bioactive metabolites: phenolic acids and SCFA. These metabolites are potentially responsible for many of the health benefits exerted by polyphenols rich foods and fibre. Given the recent advances in understanding the role of colonic microbiota in metabolic and immune responses, factors, which may positively or negatively modify the composition of the colonic bacteria have also received much attention. Foods rich in dietary fibre and polyphenols have the potential to modify colonic bacteria through prebiotic and antibiotic action. The potential bacterial inhibition by polyphenolics and the stimulation of bacterial growth by fibre and polyphenols means potential for both sets of compounds to influence metabolite production from each other. Polyphenols and fibre are most often present in the same foods and may be found together in plant cell walls. Thus they most often enter the colon together. We aimed to explore how the presence of these two components in the diet may impact on the metabolite production from the other by the colonic microbiota. Methods: The food matrix interaction of fibres and polyphenols was assessed using the fibres: raftiline, pectin and ispaghula, having different physio-chemical properties (rate of fermentation and viscosity) and the polyphenols: rutin and catechin, epicatechin and other polyphenols present in cocoa in vitro models of phenolic acid and short chain fatty acid (SCFA) production. The impact of ispaghula on urinary phenolic acids after cocoa ingestion was then investigated in an acute human study. In Chapter-3 the impact of the fermentable fibres on phenolic acid production from isolated parent compound: rutin in-vitro using 24 hour batch cultures using human faecal samples from volunteers (n=10) after being on a 3-day low polyphenol diet was investigated. Using the same model the impact of rutin, quercetin and their metabolites on SCFA production from raftiline, ispaghula and pectin was then investigate. The SCFA were measured by GC-FID and phenolic acids by GCMS. pH and gas were also measured. Using the same methodology the matrix interaction between raftiline, ispaghula and pectin separately on phenolic acid production from their parent compounds within their food matrix was investigated using cocoa as a rich source of polyphenols, as well as the impact of cocoa polyphenols and their metabolites on SCFA production from the fermentable fibres (Chapter-4) In Chapter-5, 24-hour urinary polyphenolic acids were measured in 5 batches (0, 0-2, 2-5, 5-8, 8-24 hour) in 12 human volunteers after ingestion of 1g paracetamol with 20g cocoa (extra brute Cocoa-Cacao Barry, Barry Callebaut, Hardricourt, France) with water, 15g of ispaghula with water or the combination of the two. Urine samples were also used for total phenol and antioxidant capacity measurement. Plasma was collected over six hours (every half hour for 4 hours and at 6th hour) and used for the measurement of total phenols as well as paracetamol concentrations for the estimation of gastric emptying rate. Breath hydrogen was used for estimation of small bowel transit time and visual analogue scales (VAS) were used for the estimation of subjective appetite response to meals. Results: The faecal fermentation of rutin resulted in the production of the following phenolic acids: PAA, 4-HBA, 3-HPAA, 4-HPAA, 3,4-DHPAA, 3-HPPA and 4-HPPA. All of these phenolic acids were significantly reduced by at least one of the three fibres, with the exception of 3-HPPA and 4-HPPA. The extent of inhibition of total sum of phenolic acids from raftiline and pectin was similar (p < 0.01) and ispaghula demonstrated the least inhibitory effect (p=0.03). Rutin and quercetin had no impact on the SCFA production from the fermentable fibres. The phenolic acids identified from cocoa faecal incubations consisted of: of PAA, 3-HPAA, 4-HPAA, 3,4-DHPAA, 3-HPPA, 4-HPPA, 3,4-DHPPA, 4-HBA, 3,4-DHBA, hippuric acid and vanillic acid. Unlike the rutin study where majority of phenolic acids were significantly reduced, in this study only four of eleven phenolic acids were affected (PAA, 3-HPAA, 4-HPAA, 4-HBA: also inhibited in the rutin study).The extent of phenolic acid reduction was the highest for pectin (p < 0.01), followed by raftiline (p < 0.01) and ispaghula (p=0.03). These phenolic acids or their parent compounds had no impact on SCFA production from the fermentable fibres. The consumption of cocoa resulted in the urinary excretion of the following phenolic acids: 3-HPAA, 4-HPAA, 3,4-DHPAA, Hippuric, 4-HPA, 4-HBA, 3,4-DHBA, Vanillic, 4-HVA, Mandelic and 4-HMA. All of which, with the exception of vanillic acid and 3,4-DHPAA, were reduced by ispaghula (Table-I). Ispaghula accelerated gastric emptying rate but had no impact on small bowel transit time. The analysis of total phenol (TP assay) concentration (plasma and urine) and antioxidant capacity (urine) did not demonstrate any difference between cocoa and ispaghula, which were both high. However when they were ingested together there was a signification reduction in both total phenol and antioxidant capacity (p < 0.01). Given that urinary and plasma concentration of total phenols was no different for ispaghula and cocoa we analysed the free phenolic and bound phenolics in both ispaghula and cocoa, showing that cocoa has significantly higher free phenolics than ispaghula, whereas bound phenolics were higher in ispaghula. The sum of bound and free total phenols was higher in cocoa than ispaghula (approximately 10 fold). Urinary, faecal SCFA were not measured as they are not validated to represent in-vivo production. Conclusion: there is a strong inhibition of phenolic acid production from polyphenol by the fermentable fibres and their metabolites. This inhibition is stronger in-vivo than in-vitro for ispaghula, which may reflect the longer interaction time in the colon and potential small bowel interaction. The production of SCFA from fermentable fibres was not inhibited by the polyphenols or their metabolites. These interactions need to be considered when assessing the bioavailability of phenolic acid production and their potential health benefits.
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Gustafsson, Kerstin. "Metabolic effects of fibre-rich foods studies of vegetables, oats and wheat on glucose and lipid metabolism and satiety /." Lund : Dept. of Community Health Sciences, and Dept. of Applied Nutrition and Food Chemistry, Chemical Centre, Lund University, 1994. http://catalog.hathitrust.org/api/volumes/oclc/39725793.html.
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Juneja, Prateek. "The impact of soluble dietary fibre on blood glucose, insulin and gut hormones in obese human subjects." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/35925.
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The incidence of obesity and type 2 diabetes mellitus (T2D) has been on the rise and the evidence suggests that soluble dietary fibres may be helpful for obesity management and T2D prevention. Polyglycoplex (PGX), a novel, viscous polysaccharide, has been shown in several studies to promote weight loss and exert positive effects on postprandial glycemia and satiety hormone secretions. Furthermore, recent evidence suggests a role of dietary fibres in appetite glycemic control, which may be partly mediated by gut hormones such as glucagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide (GIP), amylin, leptin, ghrelin, peptide YY (PYY) and pancreatic polypeptide (PP). These substances may aid weight loss and the maintenance of a constant plasma insulin level, which is important for obese and T2D patients.
Healthy, overweight individuals (Body Mass Index (BMI) > 27 kg/m2) were recruited for this study. Participants were randomized for 13 weeks to receive supplements, containing either 750 mg of PGX (Treatment group, n=76) or 750 mg of cellulose (Placebo group, n=72). The participants were asked to take six capsules with water before each meal. At baseline (week 0) and at week 13 of the study, after 12 hours of overnight fasting, participants consumed a test meal. Participants did not consume PGX or placebo capsules prior to breakfast on the days of a meal tolerance test. Blood samples were collected at time 0, and at 15, 30, 45, 60, 120, and 240 min after the test meal. Although previous studies carried out on the granular form of PGX suggest that it may promote acute effects of weight loss and reductions in postprandial glycemia, in this specific study, capsulated PGX did not show a statistically significant effect on body weight, BMI, blood glucose, insulin, or other hormones, in comparison with placebo. Nevertheless, PGX had statistically significant improvements for GIP and showed some positive trends in changes of leptin over ghrelin through the cross-sectional analysis. A recent study showed that PGX capsules may be more suitable for maintaining body weight and blood glucose levels due to its delayed effects and convenience.
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Wedlake, Linda Jane. "Dietary fibre in the prevention of gastrointestinal inflammation and toxicity in patients undergoing pelvic radiotherapy for cancer." Thesis, King's College London (University of London), 2015. http://kclpure.kcl.ac.uk/portal/en/theses/dietary-fibre-in-the-prevention-of-gastrointestinal-inflammation-and-toxicity-in-patients-undergoing-pelvic-radiotherapy-for-cancer(2b0827ef-906d-4b25-898f-0c19a39b1f17).html.
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Introduction: Approximately 17,000 patients a year receive radiotherapy for the pelvic cancers. Acute radiation-induced damage to normal non-cancerous tissues (toxicity) is characterised by an inflammatory response which has many pathophysiological similarities to inflammatory bowel disease (IBD). Preventing or reducing the severity of treatment-induced toxicity is of increasing importance as the number of survivors of cancer treatment increases. Dietary fibre may be an attractive option through the anti-inflammatory action of its fermentation metabolites short chain fatty acids (SCFA) and its beneficial effect on stool frequency and form. Methods: A systematic review of the efficacy of dietary fibre in the management of IBD was undertaken. The aims were firstly to identify evidence for the manipulation of dietary fibre in this inflammatory condition of the bowel as it was anticipated that little evidence would be available in patients receiving pelvic radiotherapy and secondly to gain insight as to the nutritional interventional approaches employed. A further systematic review was undertaken to identify evidence for the efficacy of dietary fibre manipulation in patients receiving pelvic radiotherapy. A 3-arm randomised controlled trial (RCT) manipulating dietary fibre intake in pelvic radiotherapy patients was subsequently carried out, powered on the difference in the change in Inflammatory Bowel Disease Questionnaire - Bowel subset (IBDQ-B) score between study groups consuming a high fibre, low fibre or habitual dietary fibre intake measured as nonstarch polysaccharide (NSP) in g/day. Other measurements included concentration of faecal SCFA at start and end of radiotherapy, daily patient-reported bowel habit using the Bristol Stool Form scale and quality of life assessed using the IBDQ tool. Results: A total of 4232 original citations were identified in the systematic review of fibre in IBD, of which 23 articles (1296 patients) were included. Evidence for the efficacy of increased dietary fibre on disease outcomes was found in 4/23 RCTs, 3/10 in ulcerative colitis and 1/1 in pouchitis. Meta-analysis was not possible due to widely differing study designs. The systematic review of fibre during pelvic radiotherapy identified 4188 original citations of which 4 articles (264 patients) were included. Meta-analysis (2 studies) showed increased or modified dietary fibre to be of benefit as a prophylactic against new-onset diarrhoea with a risk ratio of 0.75 (95% CI: 0.56 – 1.01). However, this result was not statistically significant (p=0.06). A total of 166 patients were randomised to the ‘Fibre Study’ RCT with 159 providing evaluable data of the required 156 patients. A significant difference in the change in IBDQ-B score between baseline and end of radiotherapy was identified between the high fibre and no intervention (control) group of 7.7 points in favour or the high fibre group (p=0.007). A difference in the change in IBDQ-B score of 3.4 points was also found between the low fibre and control group in favour of the low fibre group although this difference was not significant (p=0.535). No significant differences between groups were found in the incidence of loose stool (Bristol Stool type 6/7) or stool frequency although there was a marked increase in the use of anti-diarrhoeal medication by the high fibre group during week 5 of radiotherapy treatment. Mean (sd) NSP consumption of the control, low and high fibre groups at the start of radiotherapy was 13.6 (5.3), 10.2 (3.4) and 17.1 (4.8) g / day and at the end of radiotherapy was 12.2 (5.2), 8.9 (2.9) and 15.7 (5.1) g / day. No significant difference between groups in the concentration of faecal SCFA was found (n=41 paired samples) between start and end of radiotherapy. There was a significant difference in the change in IBDQ quality of life scores between the high fibre and control groups between start and end of radiotherapy in favour of the high fibre group (p=0.010). Conclusion: Dietary advice to increase fibre during pelvic radiotherapy may protect against bowel symptoms compared to no dietary advice. However, advice to reduce fibre intake may also be of benefit compared to no dietary advice. High and low fibre intakes may have differing, independent benefits in comparison to ad-libitum intake. High fibre intake did not adversely affect stool frequency or type although use of anti-diarrhoeal medication may have masked these effects. The possible placebo effect of specific dietary advice versus no dietary advice is intriguing and merits further exploration.
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Lye, Ellen Jane Davey. "Effects of dietary selenium, vitamin E, and fibre on methylmercury toxicity and kinetics in male Sprague-Dawley rats." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101619.
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Mercury is an environmental contaminant of concern, particularly for fish eating populations. The objective of this study was to assess the effects of selenium, vitamin E, and phytate on methylmercury (MeHg) toxicity and kinetics in rats. Results show that increased selenium increases McHg in the liver, kidney, and frontal lobe of the brain, while increased vitamin E increases MeHg in the kidney but lowers McHg in the liver. Increased phytate resulted in a significant increase in MeHg in the frontal lobe. Methylmercury-treated rats on all diets showed an increased trend in muscarinic acetylcholine receptor (mAChR) binding in comparison with untreated rats. There was no change in monoamine oxidase (MAO) activities in all treatment groups. These results suggest that nutrients can alter the toxicokinetics of MeHg but none of them show clear protection in neurotoxicity in adult rats.
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Luk, Alison. "The carbohydrate dimension of nutrition in gut microbiome modulation." Thesis, The University of Sydney, 2022. https://hdl.handle.net/2123/28506.
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Dietary carbohydrates that escape host digestion and are microbiota-accessible (MAC) are increasingly recognised as essential for individual and public health. Inadequate consumption of MAC is associated with the global crisis of chronic diseases. Dietary MAC supplementation has previously been used to modulate the gut microbiota to benefit host health. However, a key challenge in the application of MAC is high individual variability in response, with poor predictability of which individuals will benefit. In this thesis, my goal was to identify the factors that contributed to this variability and to identify approaches to improve the manipulation of dietary carbohydrates to modulate the gut microbiome for health.
This thesis incorporated a human observational study and four animal experimental studies. I classified four categories of carbohydrates: accessible mainly by the host, accessible by both the host and the microbiota, accessible by the microbiota only, or inaccessible to both the host and the microbiota. I tested the hypotheses that microbial and host responses to diet were dependent on the category of carbohydrate and dietary protein content.
My studies showed that despite individual variability, there were predictable elements of diet-microbiome interactions. Introducing new sources of MAC resulted in the greatest changes in the microbiome composition and metabolism, while the microbiota accessibility of diet determined the extent of change. Using ecological theory, I identified individual and dietary contributors to variability in response. Furthermore, I showed that in the context of intestinal damage, stimulating microbial activity with MAC was detrimental to health.
Overall, the outcome of MAC supplementation may beneficial, inconsequential, or harmful, and cannot be predicted without consideration of other microbiome and host factors. In conclusion, my thesis supports the paradigm shift from one-size-fits-all to the personalisation of diet.
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Adjei-Duodu, Thomas. "Physical, chemical and functional properties of tiger nuts (Cyperus esculentus) selected from Ghana, Cameroon and UK market (Spain)." Thesis, University of Plymouth, 2015. http://hdl.handle.net/10026.1/3313.
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The tiger nut (Cyperus esculentus) has attracted a lot of unsubstantiated health claims, yet there is a dearth of research investigation within Ghana specifically in the area of food product development. This study addresses the development of ‘functional bread and biscuit’ from tiger nuts obtained from UK market (Spain). The chemical constituents; carbohydrate, lipid, protein, dietary minerals and antioxidants, the functional properties of three varieties of tiger nuts obtained from Ghana (black and brown), Cameroon (yellow) and UK market (Spain) (brown) were investigated using standard analytical methods as well as the blood glucose response of healthy adults who consumed the developed bread. Tiger nuts were found to be good sources of carbohydrate (51-82g/100g) and lipids (21-37g/100g). The dietary fibre components ranged between 18, 1, 19 and 19g/100g for IDF, SDFP, HMWDF, and ITDF respectively, while the available carbohydrate as sugars were 45, 0.5 and 5g/100g for glucose, maltose and xylose respectively. Minerals that were found to be inherent to the crop were; potassium, phosphorus, magnesium, copper, iron, zinc and selenium and do not depend on place of origin. The following ratios for Sodium/Potassium 0.04, Calcium/Phosphorus 0.13 and Calcium/Magnesium 0.28 were obtained. Tiger nuts had TPC ≥ 134GAE per g, DPPH and stability index of 0.9-8.7mmol/litre and 3- 4 respectively. In conclusion the tiger nuts originating from different geographical locations were good sources of health giving minerals and had diversity of physical properties and chemical constituents which could inform future research in the functional food industry. Tiger nut could be added to the Ghana food basket and the product developed from it could be a potential functional food because of its effect on glucose response and phytochemical contents. It could again be used to replace artificial antioxidants (BHA or BHT) which are used in the food industry to inhibit lipid and protein oxidation especially the black variety.
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Len, Ninh Thi. "Evaluation of fibrous feeds for growing pigs in Vietnam : effects of fibre level and breed /." Uppsala : Dept. of Animal Nutrition and Management, Swedish University of Agricultural Sciences, 2008. http://epsilon.slu.se/200822.pdf.
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Genoni, Angela. "Health impacts and dietary composition of Paleolithic and Australian Guide to Healthy Eating Diets in Australia." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2018. https://ro.ecu.edu.au/theses/2126.
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The Paleolithic diet is promoted in Australia for improved gut health. However, it excludes grains and dairy, food groups that form part of the evidence-based Australian Guide to Healthy Eating (AGHE). While total dietary fibre intake can be maintained from consumption of vegetables, fruit and nuts, it is not known if the elimination of grain-based foods results in changes to resistant starch (RS) intake. The Paleolithic diet can be classified as a low carbohydrate diet, however, interventions examining the impact of low carbohydrate diets on gastrointestinal health have been short-term and very low in dietary fibre, limiting comparison with a Paleolithic dietary pattern. Serum trimethylamine-N-oxide (TMAO) arises mainly from colonic fermentation and hepatic conversion of animal protein and is positively associated with cardiovascular disease, but changes to RS intake may alter concentrations. With available literature on the Paleolithic diet examining only cardiometabolic and anthropometric outcomes, there exists a need to examine both fibre fraction intake and markers of gastrointestinal health, including the composition of the microbiota.
The PhD research comprised three separate studies. Studies One and Two re-examined data from a four-week randomised dietary intervention in healthy women (n=39) using the Paleolithic (n=22) and AGHE diets (n=17), to understand fibre fraction intake and to determine whether the short-term dietary change induced changes in serum TMAO concentrations. Study Three comprised a new, cross-sectional study and examined markers for dietary intake, cardiovascular and gastrointestinal health; comparing the results to a control group following a standard Australian diet. Forty-four long-term followers (>1 y) of the Paleolithic diet and 47 healthy controls were recruited; three-day weighed food records, diet history, anthropometric measures, fasting blood, 24-hour urine and 48-hour stool samples were collected. Food group, fibre and RS intake were estimated from weighed food records; serum TMAO concentrations were measured using LC-MS; faecal biochemistry with LC and GC-MS; faecal microbiota composition was analysed using 16s rRNA sequencing of the v4 region.
The short-term intervention comprising Studies One and Two showed RS intake postintervention, on a Paleolithic diet was significantly lower (RS Minimum 1.39 ± 0.95 g/day, RS Maximum 6.52 ± 4.59 g/day), than intake in the AGHE group (RS Minimum 2.46 ±2.26 g/day, RS Maximum 9.91 ± 9.06 g/day) and resulted in significant differences between groups (P
Study Three showed variation in the level of adherence to the Paleolithic diet and resulted in the stratification of the cohort into Strict Paleolithic (SP) (n=22) and Pseudo-Paleolithic (PP) (n=22) groups. Total dietary fibre intake was similar in the SP and control groups (30 g/day versus 27 g/day) and significantly higher than that of the PP group (21 g/day) (PBifidobacteriaand Roseburia genera, and increased abundance of TMA producing genera Hungatella.
Lower RS and carbohydrate intake, combined with high fat intake were associated with changes in microbiota and reduced abundances of beneficial genera in the Paleolithic group. The lack of differences between groups observed in SCFA excretion and the association with vegetable intake is supportive of dietary recommendations to increase consumption and may indicate a mechanism via which vegetables exert beneficial health impacts. The significantly higher concentrations of TMAO in the SP group and the association with both whole grain intake and the microbiota indicates that a variety of carbohydrate sources and fibre components may be required to maintain colonic health. Future research should now focus on including markers of intestinal permeability and inflammation to confirm these findings.
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Stewart, C. L. "Effects of dietary fibre and the provision of a foraging substrate on the welfare of sows in different grouping systems." Thesis, Queen's University Belfast, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492327.
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The aim of this PhD thesis was to investigate the effect of increasing dietary fibre level and the provision of foraging substrates on the welfare of sows housed in dynamic and static groups. To achieve this a review paper was compiled, and three experiments conducted. The aim of the review paper was to assess the effecti,:eness of increasing dietary fibre levels on the welfare of pregnant sows. Previous research found that increasing dietary fibre levels decreased activity levels and the performanc'e of stereotypic behaviour, and increased resting ~ehaviour. However the optimum fibrous ingredient, ,or combination of ingredients, and the optimum dietary inclusion rate for these ingredients remains unclear. The first experimental study assessed the effects of providing sows in large dynamic groups with access to straw in racks. Sows spent almost 10% of their time exploring the straw racks and consequently less time performing general exploratory behaviour. .Increased levels of aggression were observed in the straw treatment, and provision of straw had no effect on sham chewing behaviour. These findings suggest that welfare benefits associated with providing sows in large dynamic groups with access to straw racks are limited. The second experimental study assessed the effect of increasing fibre levels in the concentrate ration (to 15% crude fibre) on the welfare of sows housed in a large dynamic group. This resulted in less stereotypic behaviour and increased time spent resting. It also promoted the use of kennel areas by newly introduced sows to the group, and reduced some aggressive behaviours. Therefore, providing a high fibre diet had a positive effect on the welfare of dry sows housed in a large dynamic group. The third experiment assessed the effect of increasing dietary fibre levels (to 9% crude fibre) and providing straw in racks on the welfare of sows in small static groups. Sows offered the high fibre diet appeared to rest more, and additive benefits, in terms of reductions in stereotypic behaviour, where observed when the high fibre diet was combined with access to straw.
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Järvi, Anette. "Carbohydrate-Rich Foods in the Treatment of the Insulin Resistance Syndrome : Studies of the Importance of the Glycaemic Index and Dietary Fibre." Doctoral thesis, Uppsala University, Department of Public Health and Caring Sciences, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-1507.
Full textAbstract:
The glycaemic responses to various carbohydrate-rich foods are partly dependent on the rate at which the carbohydrate is digested and absorbed. The glycaemic index (GI) is a way of ranking foods according to their glycaemic response and is recommended as a useful tool in identifying starch-rich foods that give the most favourable glycaemic response. This investigation was undertaken to determine whether carbohydrate-rich foods with a low GI and a high content of dietary fibre (DF) could have beneficial metabolic effects in the insulin resistance syndrome. This question was addressed both in single-meal studies and in randomised controlled clinical trials. Starch-rich foods with low GI values incorporated into composite meals resulted in lower postprandial responses of both glucose and insulin than foods with a high GI in meals with an identical macronutrient and DF composition, in subjects with type 2 diabetes. After three weeks on a diet including low GI starchy foods metabolic profile was improved in subjects with type 2 diabetes, compared with a corresponding high GI diet. The glucose and insulin responses throughout the day were lower, the total and low density lipoprotein cholesterol was decreased, and the fibrinolytic activity was normalised. In subjects with impaired insulin sensitivity and diabetes low GI foods rich in soluble DF for breakfast gave a more favourable metabolic profile, with smaller glucose fluctuations from baseline during the day, than a breakfast with high GI foods low in DF. A low GI breakfast high in DF also resulted in lower responses of insulin and C-peptide after breakfast and a lower triacylglycerol response after a standardised lunch. However, none of the tested breakfasts improved the glucose and insulin responses after lunch. Similar results were obtained in obese subjects after including a breakfast with a low GI high in soluble DF for a period of four weeks in comparison with a breakfast with a high GI and low content of DF.
These results support the therapeutic potential of a diet with a low GI in the treatment of diabetes and also in the treatment of several of the metabolic disturbances related to the insulin resistance syndrome.
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Järvi, Anette. "Carbohydrate-rich foods in the treatment of the insulin resistance syndrome : studies of the importance of the glycaemic index and dietary fibre /." Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2001. http://publications.uu.se/theses/91-554-5166-7/.
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Larrosa, Capacés Susana. "Efectos sobre la salud de la ingesta de fibra y su adecuación a las recomendaciones en niños europeos." Doctoral thesis, Universitat Rovira i Virgili, 2021. http://hdl.handle.net/10803/673187.
Full textAbstract:
ngesta de fibra dietètica s'ha relacionat amb la salut digestiva i cardiovascular en adults, però hi ha poques evidències d'aquesta relació durant la infància. A més, les recomanacions d'ingesta de fibra en pediatria es basen en una extrapolació de les indicades per als adults, desconeixent-se si són adequades per a la salut en la infància. L’objectiu d’aquesta tesi doctoral va ser analitzar l’associació entre la ingesta de fibra dietètica i la seva adequació a les recomanacions durant la infància amb els marcadors de salut cardiometabòlics. Es va realitzar una anàlisi longitudinal observacional secundària a l'Assaig EU Childhood Obesity Project. Es va descriure la ingesta de fibra i les fonts (recollida a intervals regulars mitjançant diaris de 3 dies) des del naixement fins als 8 anys en participants d'Alemanya, Bèlgica, Polònia, Itàlia i Espanya. Els nens es van classificar segons el compliment de les recomanacions d'ingesta de fibra. Es va calcular el percentatge d'adequació a les recomanacions a totes les edats. Als 8 anys es va avaluar la seva antropometria, pressió arterial sistòlica (PAS) i les anàlisis bioquímiques en sang (lipoproteïnes, triglicèrids i homeòstasi per a resistència a la insulina (HOMA-IR)). La puntuació z interna d’aquests paràmetres es va sumar com a indicador de risc cardiometabòlic. Baixos consums de fibra de forma mantinguda al llarg de la infància es van relacionar amb menor tolerància a la glucosa, xifres superiors de PAS i una puntuació de risc cardiometabòlic més alta als 8 anys. Diferents fonts de fibra (fruites i verdures o llegums) es van associar amb diferents paràmetres del risc cardiometabòlic. Un percentatge elevat de la població infantil tenia ingestes de fibra inferiors a les recomanades de l'EFSA, encara que el fet de no complir-les no es va associar amb la salut cardiometabòlica en aquestes edats. No es va trobar un punt de tall específic d'ingesta de fibra associat a efectes beneficiosos sobre la salut als 8 anys que es pogués marcar com a nova recomanació. Tot i això, el fet que una ingesta mantinguda al voltant de 6.7 gr/1000 kcal al dia s'associés amb pitjors marcadors cardiometabòlics, podria suggerir que una ingesta superior a aquesta seria suficient per prevenir aquest tipus d'alteracions cardiometabòliques en edats primerenques.La ingesta de fibra dietética se ha relacionado con la salud digestiva y cardiovascular en adultos, pero existen escasas evidencias de esta relación durante la infancia. Además, las recomendaciones de ingesta de fibra en pediatría se basan en una extrapolación de las indicadas para los adultos, desconociéndose si son adecuadas para la salud en la infancia. El objetivo de esta tesis doctoral fue analizar la asociación entre la ingesta de fibra dietética y su adecuación a las recomendaciones durante la infancia con los marcadores de salud cardiometabólicos. Se realizó un análisis longitudinal observacional secundario al Ensayo EU Childhood Obesity Project. Se describió la ingesta de fibra y sus fuentes (recogida a intervalos regulares mediante diarios de 3 días) desde el nacimiento hasta los 8 años en participantes de Alemania, Bélgica, Polonia, Italia y España. Los niños se clasificaron en función del cumplimiento de las recomendaciones de ingesta de fibra. Se calculó el porcentaje de adecuación a las recomendaciones en todas las edades. A los 8 años se evaluó su antropometría, presión arterial sistólica (PAS) y los análisis bioquímicos en sangre (lipoproteínas, triglicéridos y homeostasis para resistencia a la insulina (HOMA-IR)). La puntación z interna de estos parámetros se sumó como indicador de riesgo cardiometabólico. Bajos consumos de fibra de forma mantenida a lo largo de la infancia se relacionaron con menor tolerancia a la glucosa, cifras superiores de PAS y un puntaje de riesgo cardiometabólico más alto a los 8 años. Diferentes fuentes de fibra (frutas y verduras o legumbres) se asociaron con diferentes parámetros del riesgo cardiometabólico. Un porcentaje elevado de la población infantil realizaba ingestas de fibra inferiores a las recomendadas de la EFSA, aunque el hecho de no cumplirlas no se asoció con la salud cardiometabólica en estas edades. No se halló un punto de corte específico de ingesta de fibra asociado a efectos beneficiosos sobre la salud a los 8 años que pudiera marcarse como nueva recomendación. Sin embargo, el hecho de que una ingesta mantenida alrededor de 6.7 gr/1000 kcal al día se asociase con peores marcadores cardiometabólicos, podría sugerir que una ingesta superior a ésta sería suficiente para prevenir este tipo de alteraciones cardiometabólicas en edades tempranas.
Dietary fiber intake has been associated with digestive and cardiovascular health in adults, but there is little evidence about this relationship during childhood. Furthermore, the fiber intake recommendations in pediatrics are based on an extrapolation of those indicated for adults, and it is unknown whether they are appropriate or not for children’s health. The aim of this doctoral thesis was to analyze dietary fiber intake and its adherence to recommendations in relation to cardiometabolic health markers during childhood. We performed an observational longitudinal analysis secondary to the EU Childhood Obesity Project Trial. Fiber intake and its dietary sources (collected at regular intervals using 3-day diaries) were described in participants from Germany, Belgium, Poland, Italy, and Spain from birth to 8 years. The children were classified depending on the compliance with the fiber intake recommendations. The percentage of adequacy with the recommendations was calculated at all ages. At 8 years of age, anthropometry, systolic blood pressure (SBP) and biochemical blood parameters (lipoproteins, triglycerides and homeostasis for insulin resistance (HOMA-IR)) were assessed. The internal z-score of these parameters was added as an indicator of cardiometabolic risk. Sustained low fiber intakes throughout childhood were associated with worse glucose tolerance, SBP levels, and overall cardiometabolic risk score at age 8 years. Different dietary sources of fiber (fruits and vegetables or legumes) were associated with different parameters of cardiometabolic risk. A high percentage of the child population had fiber intakes lower than those recommended by the EFSA, although not following them was not associated with cardiometabolic health at these ages. We did not find a specific cut-off point for fiber intake associated with beneficial health effects at 8 years which could be set as a new recommendation. However, the fact that an intake maintained around 6.7 g / 1000 kcal per day is associated with worse cardiometabolic markers, could suggest that an intake higher than this would be sufficient to prevent this type of cardiometabolic disturbances at an early age.
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Jones, Rosanna Frances. "The regulation of the intestinal cancer stem cell marker LGR5 by the dietary fibre derived chemopreventive agent sodium butyrate via an epigenetic mechanism." Thesis, University of Bristol, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.681727.
Full textAbstract:
The cancer stem cell hypothesis suggests that tumour growth is initiated and maintained by a subset of tumour cells that display stem cell- like properties. Stem cell markers such as Leucine-rich repeat-containing G-protein coupled receptor 5 (LGRS), a regulator and downstream target of Wnt signalling, have been identified in the normal intestinal stem cells and also in colorectal tumours. This project aimed to investigate the regulation of LGRS by epigenetic mechanisms and in particular by sodium butyrate, a dietary fibre derivative, histone deacetylase (HDAC) inhibitor and candidate chemopreventive agent. It is important to study dietary compounds as many have been reported to play a role in carcinogenesis. This investigation may therefore lead to improved chemoprevention and the development of new cancer therapies. Initially the role of DNA methylation in regulating LGRS expression in normal t issue and cancer cell lines was investigated, however, although LGRS methylation was observed in some cell lines, no evidence for the functional regulation of LGRS by methylation was found. This study hypothesised that butyrate acts as a chemopreventive agent by targeting cancer stem cells and therefore aimed to investigate the effect of butyrate on the expression of LGRS and other cancer stem cell markers. Butyrate at physiological concentrations was found to downregulate LGRS expression in colorectal cancer cell lines through inhibition of LGR5 gene transcription. This effect occurred within four hours of treatment and was reversible upon removal of butyrate. LGRS expression was also decreased by other pan and class I HDAC inhibitors such as Trichostatin A and Mocetinostat, leading to the conclusion that HDAC inhibit ion was the critical mechanism by which butyrate regulated LGRS. siRNA knockdown of individual HDACs showed that it was the inhibition of HDACl specifically that mediated this effect. Additional work in to the mechanism of butyrate action suggested that Wnt signalling is not involved in the downregulation of LGRS and further work in to other potential intermediate factors will be interesting. Finally the role of LGRS overexpression on cell growth and response to butyrate was investigated. These results suggested that in some cell lines and culture conditions LGRS may enhance cell growth and also reduce the growth inhibitory effects of butyrate. These results present a novel mechanism for the regulation of LGRS, an important cancer stem cell marker, by a well-known dietary derived chemopreventive agent and hint at a role for this effect in regulating stem cell dynamics
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Hopwood, Deborah. "Dietary fibre for the newly weaned pig: Influences on pig performance, intestinal development and expression of experimental post-weaning colibacillosis and intestinal spirochaetosis." Thesis, Hopwood, Deborah (2001) Dietary fibre for the newly weaned pig: Influences on pig performance, intestinal development and expression of experimental post-weaning colibacillosis and intestinal spirochaetosis. PhD thesis, Murdoch University, 2001. https://researchrepository.murdoch.edu.au/id/eprint/53197/.
Full textAbstract:
The diet fed in the immediate post-weaning phase influences the development of the intestinal tract and the establishment of microflora within the gut of the piglet. This development may prove beneficial to the long-term health of the pig or it may result in growth checks, diarrhoea and excessive growth of intestinal pathogens, depending on the diet fed and the stresses imposed upon the piglet. Post-weaning colibacillosis (PWC) is associated with excessive proliferation of enterotoxigenic Escherichia coli in the small intestine. These bacteria attach to enterocytes and release toxins that cause hypersecretory diarrhoea. Diarrhoea is accompanied by weight loss, anorexia, dehydration and eventually death if infection is severe. The pathogenesis of PWC is complex and multifactorial, and is heavily influenced by weaning-associated factors such as stress and the change in diet at weaning. The primary aim of this PhD study was to investigate the influence of dietary fibre on the intestinal and whole body development of healthy weaner pigs and pigs with experimental PWC. The latter animals were used to investigate the influence of fibre on the incidence of diarrhoea and the proliferation of pathogenic intestinal E. coli in experimentally infected pigs.
Physiologically, the term dietary fibre includes any plant polysaccharides that are resistant to digestion in the small intestine, instead passing into the large intestine where they are fermented. The negative control diet used in all experiments contained cooked white rice as the main ingredient because it is very low in fibre content and is highly digestible. Sources of fibre were added into this diet to create the desired level and type of dietary fibre. In experiments 2, 3 and 4, a hydrolysed rice diet was also tested as a base rice ingredient. As different facilities were used for healthy and experimental infection experiments, Chapter 3 addressed the issue of food intake with regard to the design of experiments within the project. The remainder of the thesis was divided into sections based on the particular type of dietary fibre that was being targeted. Typically, pigs were killed 1-3 weeks after weaning, and intestinal and whole body measurements made. Dietary sources of primarily insoluble fibre were first examined, followed by sources of soluble fibre, and finally purified viscous soluble sources of fibre. Each of these areas was explored with regard to the intestinal and whole body development of the healthy pig before investigating how the type of fibre affected pigs with experimental PWC. As an extension of this work to other intestinal infections, the influence of dietary soluble viscous fibre on the pathogenesis of porcine intestinal spirochaetosis (PIS), a post-weaning large intestinal infection caused by the spirochaete Brachyspira pilosicoli, was also tested.
In the healthy newly weaned pig there was rapid adaptation to the presence of increasing amounts of dietary fibre. Sources of insoluble fibre, particularly wheat and lupins, had the greatest effect on increasing the size of the large intestine and on increasing microbial fermentation, although the addition of soluble fibre (pearl barley) also was capable of significantly increasing large intestinal size and fermentative capacity compared to the base rice diet. As a result of feeding fibre sources, the carcase growth tended to suffer at the expense of intestinal growth, although all pigs expended energy into intestinal growth in the immediate post-weaning period. The ileal digestibility of nutrients at 10 days post-weaning was depressed by addition of fibre to the diet. The digestibility of crude protein and gross energy at the ileum decreased upon addition of insoluble fibre from lupins, and upon addition of resistant starch, whilst addition of pearl barley (soluble fibre) reduced the starch digestibility.
The interaction of diet with the development and expression of PWC differed according to the diet fed. Inoculation with enterotoxigenic E. coli generally reduced the whole body and intestinal growth and intestinal fermentation of all pigs, although the pigs fed the cooked white rice diet suffered the least depression in growth and consistently had drier faeces throughout all trials.
Raw wheat, as a primary dietary ingredient and source of insoluble fibre and resistant starch, did not significantly alter the proliferation of intestinal enterotoxigenic E. coli. However, extrusion of the wheat resulted in an increase in the proliferation of E. coli, as did hydrolysing the rice. Addition of pearl barley (soluble fibre source) to the cooked rice diet significantly increased the proliferation of enterotoxigenic E. coli as well as increasing the viscosity of the intestinal contents of healthy and experimentally infected pigs. Feeding a diet containing the viscous, purified polysaccharide carboxymethylcellulose (CMC) at 4% of the diet induced a natural infection of PWC without requiring experimental inoculation with enterotoxigenic E. coli. This effect was repeatable in the immediate post-weaning period but did not occur a few weeks after weaning.
This study showed that dietary fibre affects the rate of development of the intestines and the pig’s ability to utilise dietary nutrients immediately after weaning. Although increasing the amount of dietary fibre was not always detrimental to the live weight growth of the pig, the experimentally infected pigs fed the cooked rice diet (low fibre) were the only infected animals to maintain positive growth rates. The expression of PWC was increased by the addition of soluble fibre and by increasing the viscosity of the intestinal contents. This work illustrates the complex interaction of diet with the microflora of the pig’s intestinal tract, and suggests that a highly digestible, low fibre diet may be most suitable for growth and prevention of intestinal disorders in the first one to two weeks following weaning.
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Struck, Susanne. "Interactions of wheat macromolecules and fibres from fruit processing by-products using model systems and the application example muffin." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-236401.
Full textAbstract:
By-products of fruit, cereal and vegetable processing are often regarded as waste while they contain significant amounts of dietary fibre and phytochemicals that can positively contribute to the human diet when reused as food ingredient. The application of fibre from by-products in baked goods could increase the sustainability of the processing chain but is usually associated with changes in product characteristics, such as lower volume, denser structure and increased hardness. In the current study, the interactions of fibres from by-products and wheat macromolecules were analysed in muffins, starch slurries and wheat doughs. The three selected fibres differed significantly in their chemical composition and technofunctional properties. In muffins wheat flour replacement by apple fibre was assessed by rheological measurements of batter and determination of product characteristics. Water proportion adaption based on batter viscosity to create isoviscosity was evaluated as a promising method to develop muffins with satisfying characteristics, where a wheat flour replacement of 30 % is suggested. The addition of apple fibre influenced starch gelatinisation in muffins during baking as indicated by the results of pasting experiments and in vitro starch digestion. Starch slurries with apple and wheat fibre were analysed in pasting experiments. Soluble dietary fibre, mainly pectin, strongly influenced the pasting profile of wheat starch, in comparison to insoluble dietary fibre, that acted as an inert filler and did not interact with the starch. Wheat doughs with fibre from by-products were analysed for rheology, texture and microstructure. The gluten development was negatively influenced by the fibres, which resulted in less extensible doughs. Soluble dietary fibre resulted in increased dough stickiness and limited dough handling at high application levels. It can be reasoned that dough with 10% fibre from by-products would produce products with satisfying characteristics, whereas higher application levels cannot be recommended without using additives to increase the gluten strength. Fibres from by-products are suitable wheat flour replacers in bakery products, where the negative effects of the high water binding capacity of the fibre, can be partly balanced by water proportion adaption, especially in products were gluten development is not that dominating for product structure, like in muffins or cakesNebenprodukte der Obst-, Getreide- und Gemüseverarbeitung werden oft als Abfall betrachtet, wobei sie signifikante Gehalte an Ballaststoffen und sekundären Pflanzeninhaltsstoffen aufweisen, und bei der Verwendung als Lebensmittelzutat positiv zur menschlichen Ernährung beitragen können. Die Anwendung von Fasern aus Nebenprodukten in Backwaren könnte die Nachhaltigkeit der Verarbeitungskette erhöhen, ist jedoch mit Änderungen der Produkteigenschaften verbunden, wie verringertes Volumen, dichtere Struktur und erhöhte Härte. In der vorliegenden Studie wurden die Wechselwirkungen von Fasern und Weizenmakromolekülen in Muffins, Stärkesuspensionen und Weizenteigen analysiert, wobei sich die drei ausgewählten Fasern in ihrer chemischen Zusammensetzung und ihren technofunktionellen Eigenschaften unterschieden. In Muffins wurde die Mehlsubstitution durch Apfelfaser anhand von Teigrheologie und Produkteigenschaften analysiert. Die Anpassung des Wassergehaltes basierend auf der Teigviskosität wurde als vielversprechende Methode zur Entwicklung von Muffins mit akzeptablen Eigenschaften bewertet, wodurch ein Mehlersatz von 30% möglich war. Die Zugabe von Apfelfasern beeinflusste die Stärkeverkleisterung in Muffins, wie durch die Ergebnisse von Verkleisterungsexperimenten und In vitro-Stärkeverdauung gezeigt wurde. Stärkesuspensionen mit Apfel- und Weizenfasern wurden auf ihr Verkleisterungsverhalten analysiert. Lösliche Ballaststoffe beeinflussten das Verkleisterungsprofil von Weizenstärke im Vergleich zu unlöslichen Ballaststoffen, die als inerter Füllstoff fungierten und nicht mit der Stärke in Wechselwirkung traten. Weizenteige mit Fasern wurden auf Rheologie, Textur und Mikrostruktur untersucht. Die Glutenentwicklung wurde durch die Fasern negativ beeinflusst, was zu weniger dehnbaren Teigen führte. Lösliche Ballaststoffe führten zu einer erhöhten Teigklebrigkeit. Weizenteig mit 10% Faser besitzt zufriedenstellenden Eigenschaften, während höhere Fasermengen nicht zu empfehlen sind, ohne Zusatzstoffe, um die Glutenfestigkeit zu erhöhen. Fasern aus Nebenprodukten sind geeignet als Mehlersatz in Backwaren, wobei die negativen Auswirkungen der hohen Wasserbindekapazität der Faser teilweise durch Wasseranpassung ausgeglichen werden können, insbesondere in Produkten, bei denen die Glutenentwicklung nicht die Produktstruktur dominiert, wie in Muffins oder Kuchen