199 results on '"Robert A. Rastall"'
Search Results
152. Polysaccharide Degradation
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Bruce A. Stone, Birte Svensson, Michelle E. Collins, and Robert A. Rastall
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- 2008
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153. Oligosaccharides in Food and Agriculture
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Robert A. Rastall and Michelle E. Collins
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chemistry.chemical_compound ,chemistry ,Biochemistry ,business.industry ,Agriculture ,Prebiotic ,medicine.medical_treatment ,Inulin ,Food processing ,medicine ,Food science ,Biology ,business - Abstract
Oligosaccharides are an integral part of the daily diet for humans and animals. They are primarily used for their nutritional properties, however they are currently receiving much attention due to their physiological effect on the microflora of the gastrointestinal tract. Galacto-oligosaccharides and the fructan-type oligosaccharides, namely FOS and inulin are well established as beneficial to the host and are classified as prebiotic based on data from clinical studies. These compounds dominate this sector of the market, although there are oligosaccharides emerging which have produced very interesting in vitro results in terms of prebiotic status and human trials are required to strengthen the claim. Such compounds include pectic oligosaccharides, gluco-oligosaccharides, gentio-oligosaccharides, kojio-oligosaccharides, and alternan oligosaccharides. The raw materials for production of these prebiotic compounds are derived from natural sources such as plants but also from by products of the food processing industry. In addition to being prebiotic these compounds can be incorporated into foodstuffs due to the physiochemical properties they possess.
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- 2008
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154. Novel Enzyme Technology for Food Applications
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Robert A. Rastall
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chemistry.chemical_classification ,Whey protein ,Materials science ,Food industry ,Immobilized enzyme ,business.industry ,digestive, oral, and skin physiology ,Flavour ,Food technology ,Enzyme ,Biochemistry ,chemistry ,Food processing ,Food science ,Value added ,business - Abstract
Part 1 Principles of industrial enzyme technology: Discovering new industrial enzymes for food applications Improving enzyme performance in food applications Industrial enzyme production for food applications Immobilized enzyme technology for food applications Consumer attitudes towards novel enzyme technologies in food processing. Part 2 Novel enzyme technology for food applications: Using cross-linking enzymes to improve textural and other properties of food Enzymatically-modified whey protein and other protein-based fat replacers Enzymatic production of bioactive peptides from milk and whey proteins Production of flavours, flavour enhancers and other protein-based speciality products Applications of cold adapted proteases in the food industry Health-functional carbohydrates: properties and enzymatic manufacture Flavourings and other value added products from sucrose Production of novel lipids with functional health benefits The selectivity of lipases: harvesting of fatty acids and preparation of structured lipids.
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- 2007
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155. Health-functional carbohydrates: properties and enzymatic manufacture
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Simon A. Hughes and Robert A. Rastall
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Fiber intake ,Functional food ,business.industry ,Food technology ,Dietary fiber ,Food science ,Biology ,Health benefits ,business ,Intervention studies - Abstract
Publisher Summary This chapter presents that for the past 40 years, there has been an increased understanding of the sources, processing, uses, and physiological effects of dietary fiber. However, it is only since about the mid-1990s that certain dietary fibers have been awarded functional food status and have been regarded as health promoting ingredients in staple foods as well as in foods designed for the treatment of particular physiological or medical conditions. When dietary fiber is added to food, it should provide a health benefit without sacrificing the food's qualities. The chapter discusses the potential for using enzyme technology to realize and extend the health benefits of dietary fiber. Developments in enzyme technology to isolate, modify, and refine carbohydrate products enables to design enhanced forms of functional carbohydrates to increase their potential health benefits. Dietary fiber and, increasingly, prebiotics are very important for human well-being. Advances in molecular methodologies based on 16S rRNA to analyze changes in the microflora can allow for an accurate evaluation of the effect of dietary intervention studies which, combined with short-chain fatty acid (SCFA) data, can give a more complete picture on the efficacy of fiber intake.
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- 2007
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156. Characterization and in vitro digestibility of bovine β-lactoglobulin glycated with galactooligosaccharides
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Marta Corzo-Martínez, Robert A. Rastall, María Luz Sanz, F. Javier Moreno, Agustín Olano, Comunidad de Madrid, Comisión Interministerial de Ciencia y Tecnología, CICYT (España), and Consejo Superior de Investigaciones Científicas (España)
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Whey protein ,Glycosylation ,medicine.medical_treatment ,Oligosaccharides ,Prebiotic ,Lactoglobulins ,In Vitro Techniques ,β-Lactoglobulin ,chemistry.chemical_compound ,symbols.namesake ,Glycation ,Amadori rearrangement ,medicine ,Animals ,Chromatography ,Molecular mass ,Chemistry ,Galactose ,Gastrointestinal digestion ,General Chemistry ,Maillard reaction ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,symbols ,Cattle ,Digestion ,General Agricultural and Biological Sciences ,Galactooligosaccharides - Abstract
Galactooligosaccharides (GOS) are well-known prebiotic ingredients which can form the basis of new functional dairy products. In this work, the production and characterization of glycated β-lactoglobulin (β-LG) with prebiotic GOS through the Maillard reaction under controlled conditions (aw = 0.44, 40°C for 23 days) have been studied. The extent of glycation of β-LG was evaluated by formation of furosine which progressively increased with storage for up to 16 days, suggesting that the formation of Amadori compounds prevailed over their degradation. RP-HPLC-UV, SDS-PAGE, and IEF profiles of β-LG were modified as a consequence of its glycation. MALDI-ToF mass spectra of glycated β-LG showed an increase of up to ∼21% in its average molecular mass after storage for 23 days. Moreover, a decrease in unconjugated GOS (one tri-, two tetra-, and one pentasaccharide) was observed by HPAEC-PAD upon glycation. These results were confirmed by ESI MS. The stability of the glycated β-LG to in vitro simulated gastrointestinal digestion was also described and compared with that of the unglycated protein. The yield of digestion products of glycated β-LG was lower than that observed for the unglycated protein. The conjugation of prebiotic carbohydrates to stable proteins and peptides could open new routes of research in the study of functional ingredients., This work was supported by Projects 200670M027, ALIBIRD S-0505/AGR/000153 (financed by the Comunidad de Madrid), and AGL-2004-07227-C02-02 [supported by the Comisión Interministerial de Ciencia y Tecnología (CICYT)]. M.L.S. and F.J.M. are recipients of an I3P-CSIC and a Ramón & Cajal contract, respectively. M.C.-M. thanks the CSIC for an I3P Ph.D. grant.
- Published
- 2007
157. [Untitled]
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Robert A. Rastall and Sony Suwasono
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Mannosidase ,chemistry.chemical_classification ,Chromatography ,Immobilized enzyme ,Chemistry ,Stereochemistry ,Sodium ,chemistry.chemical_element ,Mannose ,Bioengineering ,General Medicine ,Oligosaccharide ,Applied Microbiology and Biotechnology ,chemistry.chemical_compound ,Enzyme ,Cellulose ,Aspergillus phoenicis ,Biotechnology - Abstract
A specific 1,2-a-mannosidase from A. phoenicis was immobilised on China clay, cellulose DE-52 and by entrapment in sodium alginate beads with respective yields of 19%, 16% and 18% in synthesis reactions consisting of 80% (w/w) mannose. Mana1→6man was the predominant product with China clay- and DE-52-immobilised enzymes with lesser amounts of mana1→2 and mana1→3. With the alginate bead-immobilised enzyme, mana1→2 was the predominant linkage formed.
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- 1998
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158. Influence of glycosidic linkages and molecular weight on the fermentation of maltose-based oligosaccharides by human gut bacteria
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Glenn R. Gibson, Gregory L. Côté, Robert A. Rastall, and María Luz Sanz
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Polymers ,medicine.medical_treatment ,Oligosaccharides ,Dextransucrase ,chemistry.chemical_compound ,Feces ,Structure-Activity Relationship ,medicine ,Humans ,Glycosides ,Maltose ,chemistry.chemical_classification ,biology ,Bacteria ,Prebiotic ,Glycosidic bond ,General Chemistry ,Oligosaccharide ,biology.organism_classification ,Alternansucrase ,Intestines ,Molecular Weight ,Biochemistry ,chemistry ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Fermentation ,General Agricultural and Biological Sciences - Abstract
A structure-function study was carried out to increase knowledge of how glycosidic linkages and molecular weights of carbohydrates contribute toward the selectivity of fermentation by gut bacteria. Oligosaccharides with maltose as the common carbohydrate source were used. Potentially prebiotic alternansucrase and dextransucrase maltose acceptor products were synthesized and separated into different molecular weights using a Bio-gel P2 column. These fractions were characterized by matrix-assisted laser desorption/ionization time-of-flight. Nonprebiotic maltooligosaccharides with degrees of polymerization (DP) from three to seven were commercially obtained for comparison. Growth selectivity of fecal bacteria on these oligosaccharides was studied using an anaerobic in vitro fermentation method. In general, carbohydrates of DP3 showed the highest selectivity towards bifidobacteria; however, oligosaccharides with a higher molecular weight (DP6-DP7) also resulted in a selective fermentation. Oligosaccharides with DPs above seven did not promote the growth of "beneficial" bacteria. The knowledge of how specific structures modify the gut microflora could help to find new prebiotic oligosaccharides.
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- 2006
159. Enzymatic Synthesis of Oligosaccharides
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Robert A. Rastall and Vatsala Maitin
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Biochemistry ,Chemistry ,Enzymatic synthesis - Published
- 2006
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160. Use of genetically modified microbes for human health
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Gregor Reid, Harsharn S. Gill, Mary Ellen Sanders, Glenn R. Gibson, Ian Rowland, Robert A. Rastall, and Todd R. Klaenhammer
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Genetics ,Human health ,law ,Immunology ,Recombinant DNA ,Disease ,Biology ,humanities ,Genetically modified organism ,law.invention - Abstract
Sir , The publication by Ott et al. (1) restates the important, and topical, use of microbes in treating disease, in this case lymphoid immunodeficiencies. However, not everyone agrees that recombinant bacteria should be used in humans, and one particular submission to this journal called for a ban of such uses, a viewpoint that we wish to now strongly challenge (2).
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- 2006
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161. Selective fermentation of gentiobiose-derived oligosaccharides by human gut bacteria and influence of molecular weight
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María Luz, Sanz, Gregory L, Côté, Glenn R, Gibson, and Robert A, Rastall
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Intestines ,Molecular Weight ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Dietary Supplements ,Fermentation ,Humans ,Oligosaccharides ,Digestion ,Disaccharides ,In Situ Hybridization, Fluorescence - Abstract
Gentiooligosaccharides and alternansucrase gentiobiose acceptor products were fractionated by their degree of polymerization (DP) on a Bio-Gel P2 column. Fractions were characterized by matrix-assisted laser desorption ionization time-of-flight mass spectroscopy, and incubated with human faecal bacteria under anaerobic conditions at 37 degrees C. The growth of predominant gut bacteria on the oligosaccharides was evaluated by fluorescence in situ hybridization and a prebiotic index (PI) was calculated. Lower DP gentiooligosaccharides (DP2-3) showed the highest selectivity (PI of 4.89 and 3.40, respectively), whereas DP4-5 alternansucrase gentiobiose acceptor products generated the greatest values (PI of 5.87). The production of short-chain fatty acids was also determined during the time course of the reactions. The mixture of DP6-10 alternansucrase gentiobiose acceptor products generated the highest levels of butyric acid but the lowest levels of lactic acid. Generally, for similar molecular weights, alternansucrase gentiobiose acceptor products gave higher PI values than gentiooligosaccharides.
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- 2006
162. In Vitro Determination of Prebiotic Properties of Oligosaccharides Derived from an Orange Juice Manufacturing By-Product Stream
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M. P. Yadhav, M. Pinart, K. Manderson, W. E. Grace, W. Widmer, Kieran Tuohy, Arland T. Hotchkiss, Robert A. Rastall, and Glenn R. Gibson
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food.ingredient ,Pectin ,medicine.medical_treatment ,Population ,Carboxylic Acids ,Oligosaccharides ,Butyrate ,Orange (colour) ,Applied Microbiology and Biotechnology ,Beverages ,Feces ,food ,fluids and secretions ,medicine ,Humans ,education ,Orange juice ,chemistry.chemical_classification ,education.field_of_study ,Ecology ,Chemistry ,Eubacterium ,Prebiotic ,Monosaccharides ,Oligosaccharide ,Physiology and Biotechnology ,Chromatography, Ion Exchange ,Biochemistry ,Fermentation ,Pectins ,Bifidobacterium ,Food Science ,Biotechnology ,Citrus sinensis - Abstract
Fermentation properties of oligosaccharides derived from orange peel pectin were assessed in mixed fecal bacterial culture. The orange peel oligosaccharide fraction contained glucose in addition to rhamnogalacturonan and xylogalacturonan pectic oligosaccharides. Twenty-four-hour, temperature- and pH-controlled, stirred anaerobic fecal batch cultures were used to determine the effects that oligosaccharides derived from orange products had on the composition of the fecal microbiota. The effects were measured through fluorescent in situ hybridization to determine changes in bacterial populations, fermentation end products were analyzed by high-performance liquid chromatography to assess short-chain fatty acid concentrations, and subsequently, a prebiotic index (PI) was determined. Pectic oligosaccharides (POS) were able to increase the bifidobacterial and Eubacterium rectale numbers, albeit resulting in a lower prebiotic index than that from fructo-oligosaccharide metabolism. Orange albedo maintained the growth of most bacterial populations and gave a PI similar to that of soluble starch. Fermentation of POS resulted in an increase in the Eubacterium rectale numbers and concomitantly increased butyrate production. In conclusion, this study has shown that POS can have a beneficial effect on the fecal microflora; however, a classical prebiotic effect was not found. An increase in the Eubacterium rectale population was found, and butyrate levels increased, which is of potential benefit to the host.
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- 2005
163. Caseinoglycomacropeptide inhibits adhesion of pathogenic Escherichia coli strains to human cells in culture
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Glenn R. Gibson, K. Formentin, Robert A. Rastall, Michael Beer, N. Greenberg, and Jonathan Rhoades
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Lactobacillus casei ,Cells ,Lactobacillus pentosus ,Adenocarcinoma ,Lactobacillus gasseri ,medicine.disease_cause ,Bacterial Adhesion ,Microbiology ,Lactobacillus acidophilus ,Pathogenic Escherichia coli ,Cell Line, Tumor ,Genetics ,medicine ,Escherichia coli ,Humans ,Enteropathogenic Escherichia coli ,Desulfovibrio desulfuricans ,biology ,food and beverages ,Caseins ,biology.organism_classification ,Enterobacteriaceae ,Peptide Fragments ,Lactobacillus ,Colonic Neoplasms ,bacteria ,Animal Science and Zoology ,Food Science - Abstract
Caseinoglycomacropeptide (CGMP) derived from kappa-casein was investigated for its ability to inhibit the adhesion of 3 strains of verotoxigenic Escherichia coli (VTEC) and 3 strains of enteropathogenic Escherichia coli (EPEC) to human HT29 tissue cell cultures. Effects on adhesion of Desulfovibrio desulfuricans, Lactobacillus pentosus, Lactobacillus casei, Lactobacillus acidophilus, and Lactobacillus gasseri were also investigated. Generally, CGMP exerted effective anti-adhesive properties at a dose of 2.5 mg/mL, albeit with a high degree of strain specificity. The CGMP reduced adhesion of VTEC strains to
- Published
- 2005
164. Modulation of the microbial ecology of the human colon by probiotics, prebiotics and synbiotics to enhance human health
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Ian Rowland, Mary Ellen Sanders, Gregor Reid, Glenn R. Gibson, Bruno Pot, Fransisco Guarner, Todd R. Klaenhammer, Harsharnjit S. Gill, Robert A. Rastall, Industrial Microbiology, and Department of Bio-engineering Sciences
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Colon ,Synbiotics ,Ecology (disciplines) ,medicine.medical_treatment ,Biology ,Applied Microbiology and Biotechnology ,Microbiology ,law.invention ,Probiotic ,Human health ,Microbial ecology ,law ,medicine ,Colon/drug effects ,Humans ,Ecology ,business.industry ,Probiotics/chemistry ,Probiotics ,Prebiotic ,developing countries ,Biotechnology ,Microbial population biology ,Drug and Narcotic Control ,business ,Human colon - Abstract
The application of probiotics and prebiotics to the manipulation of the microbial ecology of the human colon has recently seen many scientific advances. The sequencing of probiotic genomes is providing a wealth of new information on the biology of these microorganisms. In addition, we are learning more about the interactions of probiotics with human cells and with pathogenic bacteria. An alternative means of modulating the colonic microbial community is by the use of prebiotic oligosaccharides. Increasing knowledge of the metabolism of prebiotics by probiotics is allowing us to consider specifically targeting such dietary intervention tools at specific population groups and specific disease states.
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- 2005
165. Synthesis of galacto-oligosaccharide from lactose using beta-galactosidase from Kluyveromyces lactis: Studies on batch and continuous UF membrane-fitted bioreactors
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Suwimol Chockchaisawasdee, Robert A. Rastall, Keshavan Niranjan, and Vasileios I. Athanasopoulos
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Ultrafiltration ,Oligosaccharides ,Bioengineering ,Lactose ,Applied Microbiology and Biotechnology ,chemistry.chemical_compound ,Kluyveromyces ,Bioreactors ,Bioreactor ,Beta-galactosidase ,chemistry.chemical_classification ,Kluyveromyces lactis ,Chromatography ,biology ,Membrane reactor ,Galactose ,Oligosaccharide ,biology.organism_classification ,beta-Galactosidase ,chemistry ,Biochemistry ,Fermentation ,biology.protein ,Biotechnology - Abstract
A study of galacto-oligosaccharides (GOS) synthesis from lactose with beta-galactosidase from Kluyveromyces lactis (Maxilact L2000) was carried out. The synthesis was performed using various initial lactose concentrations ranging from 220 to 400 mg/mL and enzyme concentrations ranging from 3 to 9 U/mL, and was investigated at 40 degrees C and pH 7, in a stirred-tank reactor. In the experimental range examined, the results showed the amount of GOS formed depended on lactose concentration but not on enzyme concentration. Galactose was a competitive inhibitor, while glucose was a non-competitive inhibitor. In a further study, a laboratory-scale reactor system, fitted with a 10-kDa NMWCO composite regenerated cellulose membrane, was used in a continuous process. The reactor was operated in cross-flow mode. The effect of operating pressures on flux and productivity was investigated by applying different transmembrane pressures to the system. The continuous process showed better production performance compared to the batch synthesis with the same lactose and enzyme concentrations at 40 degrees C, pH 7. Comparison of product structures from batch and continuous processes, analyzed by HPAE-PAD and methylation analysis, showed similarities but differed from the structures found in a commercial GOS product (Vivinal GOS).
- Published
- 2005
166. Synthesis of isomaltooligosaccharides and oligodextrans in a recycle membrane bioreactor by the combined use of dextransucrase and dextranase
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Julian M. Cooper, Goulas Athanasios K, Robert A. Rastall, and Alistair S. Grandison
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Sucrose ,Ultrafiltration ,Oligosaccharides ,Bioengineering ,Membrane bioreactor ,Applied Microbiology and Biotechnology ,Dextranase activity ,Dextransucrase ,Bioreactors ,Enzyme Stability ,Equipment Reuse ,Dextranase ,Chromatography ,Membrane reactor ,Chemistry ,Isomaltooligosaccharide ,Dextrans ,Membranes, Artificial ,Equipment Design ,Enzymes, Immobilized ,Enzyme Activation ,Equipment Failure Analysis ,Membrane ,Glucosyltransferases ,Biotechnology - Abstract
A recycle ultrafiltration membrane reactor was used to develop a continuous synthesis process for the production of isomaltooligosaccharides (IMO) from sucrose, using the enzymes dextransucrase and dextranase. A variety of membranes were tested and the parameters affecting reactor stability, productivity, and product molecular weight distribution were investigated. Enzyme inactivation in the reactor was reduced with the use of a non-ionic surfactant but its use had severe adverse effects on the membrane pore size and porosity. During continuous isomaltooligosaccharide synthesis, dextransucrase inactivation was shown to occur as a result of the dextranase activity and it was dependent mainly on the substrate availability in the reactor and the hydrolytic activity of dextranase. Substrate and dextranase concentrations (50-200 mg/mL(-1) and 10-30 U/mL(-1), respectively) affected permeate fluxes, reactor productivity, and product average molecular weight. The oligodextrans and isomaltooligosaccharides formed had molecular weights lower than in batch synthesis reactions but they largely consisted of oligosaccharides with a degree of polymerization (DP) greater than 5, depending on the synthesis conditions. No significant rejection of the sugars formed was shown by the membranes and permeate flux was dependent on tangential flow velocity.
- Published
- 2004
167. Improving gut health in the elderly
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K. Manderson, Eleni Likotrafiti, Glenn R. Gibson, Kieran Tuohy, and Robert A. Rastall
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Intestinal microorganisms ,Biology ,Microbiology - Published
- 2004
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168. Carbohydrate preferences of Bifidobacterium species isolated from the human gut
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Richard J, Palframan, Glenn R, Gibson, and Robert A, Rastall
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Xylose ,Species Specificity ,Probiotics ,Fermentation ,Carbohydrate Metabolism ,Humans ,Oligosaccharides ,Bifidobacterium ,Fatty Acids, Volatile ,Digestive System - Abstract
The growth of nine species of Bifidobacterium on media containing glucose, xylose, xylooligosaccharides (XOS), xylan or fructooligosaccharides (FOS) as the sole carbon source were compared in pure culture. The bifidobacteria differed in fermentation profiles when tested on different carbohydrates. All species grew to their highest final optical density (OD) on a glucose containing medium, with the exception of B. catenulatum which demonstrated a preference for xylose over glucose, and XOS over FOS. B. bifidum grew to the highest OD on XOS compared to xylose suggesting a specific transport system for the oligosaccharide over the monomer. This is consistent with a lack of beta-xylosidase activity present in the culture medium. Lactate, formate and acetate levels were determined and the ratios of these metabolites altered between and within species growing on different carbohydrates. In general, high lactate production correlated with low formate production and low lactate concentrations were obtained at higher levels of formate. Bifidobacteria may alter their metabolic pathways based upon the carbohydrates that are available for their use.
- Published
- 2003
169. Oligosaccharides in Food and Agriculture
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Glenn R. Gibson, Mark Williams, Estibaliz Olano-Martin, Robert A. Rastall, W. E. Grace, and Arland T. Hotchkiss
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Ultrafiltration (renal) ,Polymerization ,Chemistry ,Enzyme reactor ,Prebiotic ,medicine.medical_treatment ,medicine ,Food science ,Orange (colour) - Abstract
Pectic oligosaccharides were observed to have bifidogenic prebiotic properties. Pectic oligosaccharides were also found to possess anti-adhesive properties for food pathogen toxins and they stimulated apoptosis of colon cancer cells. Orange peel albedo (white part) was a good source of pectic oligosaccharides with prebiotic properties. Microwave and autoclave extraction produced pectic oligosaccharides with higher degrees of polymerization than those produced with an ultrafiltration dead-end membrane enzyme reactor. We propose that these larger orange albedo pectic oligosaccharides may have greater persistence through the colon, making them excellent candidates for second generation prebiotic product development.
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- 2003
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170. Pectic Oligosaccharides as Prebiotics
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Arland T. Hotchkiss, Estibaliz Olano-Martin, William E. Grace, Glenn R. Gibson, and Robert A. Rastall
- Published
- 2003
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171. Potential for the Development of Prebiotic Oligosaccharides from Biomass
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Robert A. Rastall and Arland T. Hotchkiss
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- 2003
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172. Pectin and pectic-oligosaccharides induce apoptosis in in vitro human colonic adenocarcinoma cells
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Estibaliz, Olano-Martin, Gerald H, Rimbach, Glenn R, Gibson, and Robert A, Rastall
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Caspase 3 ,Caspases ,Colonic Neoplasms ,Humans ,Oligosaccharides ,Pectins ,Apoptosis ,Adenocarcinoma ,HT29 Cells ,Cell Division - Abstract
Dietary fibres have been associated with decreased risk of various cancers, although the mechanisms are unclear. Induction of apoptosis in tumour cells is thought to be an important protective mechanism against colorectal cancer. This work investigates the effects of pectins and pectic-oligosaccharides (POS) on the human colonic adenocarcinoma cell line HT29.The anti-proliferative effects of pectin and POS were studied by testing the HT29 cells for cytotoxicity, differentiation and/or apoptosis by lactate dehydrogenase, alkaline phosphatase and caspase-3 activity assays. DNA agarose gel electrophoresis was also carried out.A significant reduction in attached cell numbers was observed after three days incubation. This decrease was neither due to cells undergoing necrosis nor differentiation. Increased apoptosis frequency, after incubation with 1% (w/v) pectin and/or POS, was demonstrated by caspase-3 activity and DNA laddering on agarose gel electrophoresis.Dietary pectins and their degradation products may contribute to the reported protective effects of fruits against colon cancer.
- Published
- 2003
173. Pectins and pectic-oligosaccharides inhibit Escherichia coli O157:H7 Shiga toxin as directed towards the human colonic cell line HT29
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Robert A. Rastall, Estibaliz Olano-Martin, Glenn R. Gibson, and Mark Williams
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Oligosaccharides ,medicine.disease_cause ,Escherichia coli O157 ,Microbiology ,Shiga Toxin 2 ,chemistry.chemical_compound ,Shiga-like toxin ,Enzymatic hydrolysis ,Genetics ,medicine ,Humans ,Molecular Biology ,Escherichia coli ,Escherichia coli Infections ,chemistry.chemical_classification ,biology ,Virulence ,Toxin ,Shiga toxin ,Oligosaccharide ,biology.organism_classification ,Enterobacteriaceae ,chemistry ,Biochemistry ,Toxicity ,biology.protein ,Pectins ,HT29 Cells - Abstract
Pectins and pectic-oligosaccharides, as derived by controlled enzymatic hydrolysis, were evaluated for their ability to interfere with the toxicity of Shiga-like toxins from Escherichia coli O157:H7. Both types of material resulted in some degree of protection but this was significantly higher (P0.01) with the oligosaccharide fractions (giving 90-100% cell survival, compared to 70-80% with the polymer). An effect of methylation on the protective effect was detected with lower degrees being more active. The pectic-oligosaccharides and galabiose, the minimum toxin receptor analogue, were shown to inhibit toxicity and were both protective at 10 mg x ml(-1), but not at lower concentrations.
- Published
- 2003
174. One-Pot Synthesis of Multivalent Arrays of Mannose Mono- and Disaccharides
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Sadie D. Osborne, Wayne Hayes, Helen M. I. Osborn, Robert A. Rastall, and Barbara Romagnoli
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Chemistry ,Organic Chemistry ,Fimbria ,One-pot synthesis ,Mannose ,General Medicine ,biochemical phenomena, metabolism, and nutrition ,Biochemistry ,Combinatorial chemistry ,chemistry.chemical_compound ,fluids and secretions ,Dendrimer ,Drug Discovery ,Anti infectives ,bacteria ,Selection (genetic algorithm) - Abstract
The synthesis of a selection of multivalent arrays of mannose mono- and disaccharides, that are of potential use as anti-infective agents against enterobacteria infections, is described.
- Published
- 2003
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175. Prebiotics and synbiotics: towards the next generation
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Vatsala Maitin and Robert A. Rastall
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Aging ,Synbiotics ,medicine.medical_treatment ,Biomedical Engineering ,Oligosaccharides ,Bioengineering ,Biology ,Health outcomes ,Feces ,Structure-Activity Relationship ,Functional food ,Species Specificity ,medicine ,Humans ,Food science ,Aged ,Gut microflora ,Bacteria ,business.industry ,Prebiotic ,Probiotics ,Infant, Newborn ,Infant ,Middle Aged ,Biotechnology ,Intestines ,Bifidobacterium ,business ,Genetic Engineering - Abstract
Recent research in the area of prebiotic oligosaccharides and synbiotic combinations with probiotics is leading towards a more targeted development of functional food ingredients. Improved molecular techniques for analysis of the gut microflora, new manufacturing biotechnologies, and increased understanding of the metabolism of oligosaccharides by probiotics are facilitating development. Such developments are leading us to the time when we will be able to rationally develop prebiotics and synbiotics for specific functional properties and health outcomes.
- Published
- 2002
176. Comparison of the in vitro bifidogenic properties of pectins and pectic-oligosaccharides
- Author
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Robert A. Rastall, Glenn R. Gibson, and Estibaliz Olano-Martin
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animal structures ,food.ingredient ,Pectin ,medicine.medical_treatment ,Oligosaccharides ,Polysaccharide ,Applied Microbiology and Biotechnology ,Methylation ,Feces ,food ,medicine ,Humans ,Bifidobacterium ,chemistry.chemical_classification ,biology ,Bacteria ,Prebiotic ,Probiotics ,food and beverages ,Actinomycetaceae ,General Medicine ,Oligosaccharide ,Hydrogen-Ion Concentration ,biology.organism_classification ,carbohydrates (lipids) ,Biochemistry ,chemistry ,Bifidobacterium angulatum ,Fermentation ,Pectins ,Biotechnology - Abstract
Aims: To compare the in vitro fermentation properties of pectins and oligosaccharides derived from them in pure and mixed faecal cultures. Methods and Results: Specific growth rates of selected bacterial genera were calculated in pure culture. Bifidobacterium angulatum, B. infantis and B. adolescentis had higher growth rates on pectic oligosaccharides (POS I) derived from high methylated pectin (HMP) than on HMP and B. pseudolongum and B. adolescentis on pectic oligosaccharides (POS II) derived from low methylated pectin than on HMP. Controlled pH batch mixed faecal cultures were then carried out and a prebiotic index was calculated as a mean to compare the fermentation properties of the different substrates. In general, greater fermentation selectivity was obtained with lower degrees of methylation (PI24-HMP = −0·11, PI24-LMP = 0·033; PI24-POS I = 0·071 and PI24-POS II = 0·092). An effect of size on prebiotic potential was observed, with the oligosaccharides having more selective fermentation properties than the pectins they derived from. Conclusions: The degree of methylation plays an important role in the fermentation properties of pectins. Pectic-oligosaccharides are a better prebiotic candidate than the pectins, although their bifidogenic effect is low compared to oligofructose. Significance and Impact of the Study: The effect of size on prebiotic potential was demonstrated. Non-selectively fermented polysaccharides like pectin can have their bifidogenic properties improved by partial hydrolysis.
- Published
- 2002
177. PECTIC OLIGOSACCHARIDES AN ANTI-ADHESIVE PREBIOTICS
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Glenn R. Gibson, Mark Williams, Estibaliz Olano-Martin, Arland T. Hotchkiss, Robert A. Rastall, and William E. Grace
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Biochemistry ,Chemistry ,Anti adhesive - Published
- 2002
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178. A comparative in vitro evaluation of the fermentation properties of prebiotic oligosaccharides
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Catherine Rycroft, Glenn R. Gibson, Robert A. Rastall, and M.R. Jones
- Subjects
medicine.medical_treatment ,Inulin ,Microbial metabolism ,Oligosaccharides ,Biology ,Applied Microbiology and Biotechnology ,Clostridia ,chemistry.chemical_compound ,Lactulose ,Feces ,fluids and secretions ,medicine ,Humans ,In Situ Hybridization, Fluorescence ,chemistry.chemical_classification ,Bacteria ,Prebiotic ,Probiotics ,Fatty Acids ,food and beverages ,Fatty acid ,General Medicine ,Oligosaccharide ,biology.organism_classification ,Culture Media ,chemistry ,Biochemistry ,Fermentation ,Biotechnology ,medicine.drug - Abstract
Aims: Comparison of in vitro fermentation properties of commercial prebiotic oligosaccharides. Methods and Results: Populations of predominant gut bacterial groups were monitored over 24 h of batch culture through fluorescent in-situ hybridization. Short-chain fatty acid and gas production were also measured. All prebiotics increased the numbers of bifidobacteria and most decreased clostridia. Xylo-oligosaccharides and lactulose produced the highest increases in numbers of bifidobacteria whilst fructo-oligosaccharides produced the highest populations of lactobacilli. Galacto-oligosaccharides (GOS) resulted in the largest decreases in numbers of clostridia. Short-chain fatty acid generation was highest on lactulose and GOS. Gas production was lowest on isomalto-oligosaccharides and highest on inulin. Conclusions: The oligosaccharides differed in their fermentation characteristics. Isomalto-oligosaccharides and GOS were effective at increasing numbers of bifidobacteria and lactate whilst generating the least gas. Significance and Impact of the Study: The study provides comparative data on the properties of commercial prebiotics, allowing targeting of dietary intervention for particular applications and blending of oligosaccharides to enhance overall functionality.
- Published
- 2001
179. Fermentation properties of gentio-oligosaccharides
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Glenn R. Gibson, M.R. Jones, Robert A. Rastall, and Catherine Rycroft
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medicine.medical_treatment ,Oligosaccharides ,Applied Microbiology and Biotechnology ,law.invention ,Clostridia ,Probiotic ,chemistry.chemical_compound ,fluids and secretions ,law ,Polysaccharides ,medicine ,chemistry.chemical_classification ,biology ,Bacteria ,Prebiotic ,digestive, oral, and skin physiology ,food and beverages ,Fatty acid ,biology.organism_classification ,Maltodextrin ,Fatty Acids, Volatile ,Biochemistry ,chemistry ,Fermentation ,Bacteroides - Abstract
C.E. RYCROFT, M.R. JONES, G.R. GIBSON AND R.A. RASTALL. 2001. Aims: To investigate the fermentation properties of gentio-oligosaccharides (GOS), as compared to fructo-oligosaccharides (FOS) and maltodextrin in mixed faecal culture. Methods and Results: The substrates were incubated in 24 h batch culture fermentations of human faecal bacteria. Fluorescent in situ hybridization was used to determine changes in populations of bifidobacteria, lactobacilli, clostridia, bacteroides, streptococci and Escherichia coli. Gas and short-chain fatty acid (SCFA) production was also measured. GOS gave the largest significant increases in bifidobacteria, lactobacilli and total bacterial numbers during the incubations. However, FOS appeared to be a more selective prebiotic as it did not significantly stimulate growth of bacterial groups which were not probiotic in nature. GOS and maltodextrin produced the highest levels of SCFA. Lowest gas production was seen with GOS and highest with FOS. Conclusions: GOS possessed bifidogenic activity in vitro. Although fermentation of GOS was not as selective as FOS, gas production was lower. Gas production is often seen as an undesirable side effect of prebiotic consumption. Significance and Impact of the Study: The study has provided the first data on fermentation of GOS in mixed faecal culture. The study has also used molecular microbiology methods (FISH) to quantify bacterial groups. The data extend our knowledge of the selectivity of fermentation of oligosaccharides by the gut microflora.
- Published
- 2001
180. Evaluation of solid substrates for enzyme production by Coriolus versicolor, for use in bioremediation of chlorophenols in aqueous effluents
- Author
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Christine S. Evans, M. A. Ullah, Robert A. Rastall, and H. Kadhim
- Subjects
Applied Microbiology and Biotechnology ,Husk ,Substrate Specificity ,chemistry.chemical_compound ,Bioremediation ,Botany ,Phenols ,Effluent ,Triticum ,chemistry.chemical_classification ,Laccase ,Aqueous solution ,Bran ,Chemistry ,Basidiomycota ,General Medicine ,Pulp and paper industry ,Wood ,Culture Media ,Enzyme ,Biodegradation, Environmental ,Edible Grain ,Oxidoreductases ,Biotechnology ,Chlorophenols - Abstract
In the development of a system for the removal of chlorophenols from aqueous effluents, a range of solid substrates for the growth of Coriolus versicolor were investigated. Substrates included wood chips, cereal grain, wheat husk and wheat bran. Suitability for transformation of chlorophenols depended on laccase production by the fungus. The greatest amount of laccase (25 Units g(-1) substrate) was produced on wheat husk and wheat bran over 30 days colonisation. Aqueous extracts of laccase from wheat husk and wheat bran cultures removed 100% of 2,4-dichlorophenol (50 ppm) from solution within 5 h and 75-80% of pentachlorophenol (50 ppm) within 24 h. Wheat bran was formulated into pellets with biscuit flour to provide a compact substrate for fungal immobilisation. Addition of 8-12% yeast extract to the pellets increased laccase production five-fold. Colonised pellets were added to chlorophenol solutions in 200-4000-ml bioreactors, resulting in90% removal of chlorophenols within 100 min.
- Published
- 2001
181. The Role of Prebiotics in Human Gut Microbiology
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Glenn R. Gibson, Catherine Rycroft, and Robert A. Rastall
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Clostridia ,medicine.anatomical_structure ,Human gut ,Host (biology) ,Microorganism ,medicine ,Microbial metabolism ,Large intestine ,Fermentation ,Biology ,biology.organism_classification ,Bacteria ,Microbiology - Abstract
The human large intestine is an intensely colonised area. This is because the colon contains a vast array of microorganisms, thought to represent the majority of all cells in the body. The nutritional, biological and clinical importance of bacteria resident in the gut is becoming increasingly recognised. Although it is known that many disease states involve bacterial metabolism, the human gut microflora may also be considered as relevant to an improvement in host health and welfare. Gut bacteria carry out a multi-disciplinary process known as fermentation, where dietary and indigenously produced residues are metaboiised to a variety of different end products. The numerically predominant (culturable) anaerobes in the gut are Gram-negative rods belonging to the genus Bacteroides. Other groups which have been identified as significant include bifidobacteria, clostridia, eubacteria, lactobacilli, Gram-positive cocci, coliforms, methanogens and dissimilatory sulphate-reducing bacteria. It is thought that several hundred different bacterial species are present in the human large intestine.
- Published
- 2001
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182. A Comprehensive Investigation of The Synthesis of Prebiotic Galactooligosaccharides by Whole Cells of Bifidobacterium bifidum NCIMB 41171
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Dimitris Charalampopoulos, George Tzortzis, Robert A. Rastall, and Ali Osman
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Hot Temperature ,Time Factors ,medicine.medical_treatment ,ved/biology.organism_classification_rank.species ,Oligosaccharides ,Lactose ,Bioengineering ,Models, Biological ,Applied Microbiology and Biotechnology ,Hydrolysis ,chemistry.chemical_compound ,Bioreactors ,medicine ,Food science ,Bifidobacterium ,Analysis of Variance ,Bifidobacterium bifidum ,biology ,Chemistry ,ved/biology ,Prebiotic ,Galactose ,Reproducibility of Results ,Actinomycetaceae ,General Medicine ,beta-Galactosidase ,biology.organism_classification ,Prebiotics ,Biochemistry ,Yield (chemistry) ,Regression Analysis ,Biotechnology - Abstract
The synthesis of galactooligosaccharides (GOS) by whole cells of Bifidobacterium bifidum NCIMB 41171 was investigated by developing a set of mathematical models. These were second order polynomial equations, which described responses related to the production of GOS constituents, the selectivity of lactose conversion into GOS, and the relative composition of the produced GOS mixture, as a function of the amount of biocatalyst, temperature, initial lactose concentration, and time. The synthesis reactions were followed for up to 36 h. Samples were withdrawn every 4 h, tested for β-galactosidase activity, and analysed for their carbohydrate content. GOS synthesis was well explained by the models, which were all significant (P
- Published
- 2010
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183. In vitro fermentability of dextran, oligodextran and maltodextrin by human gut bacteria
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Glenn R. Gibson, Robert A. Rastall, Estibaliz Olano-Martin, and K.C. Mountzouris
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medicine.medical_treatment ,Medicine (miscellaneous) ,Oligosaccharides ,Butyrate ,Biology ,chemistry.chemical_compound ,fluids and secretions ,Enterobacteriaceae ,medicine ,Humans ,Food science ,Intestinal Mucosa ,chemistry.chemical_classification ,Nutrition and Dietetics ,Prebiotic ,food and beverages ,Dextrans ,Oligosaccharide ,Carbohydrate ,Maltodextrin ,biology.organism_classification ,Intestines ,Butyrates ,Lactobacillus ,Dextran ,chemistry ,Biochemistry ,Fermentation ,Bifidobacterium ,Bacteria - Abstract
Anaerobic batch culture fermenters were used for a preliminary screening of the in vitro utilization by human gut microflora of dextran and novel oligodextrans (I, II and III) produced in the University of Reading (UK). Glucose and fructooligosaccharides (FOS) were used as reference carbohydrates. As expected, FOS acted as a good prebiotic in that it selectively increased numbers of bifidobacteria in the early stages of the fermentation. Dextran and oligodextrans each resulted in an enrichment of bifidobacteria in the batch cultures, with high levels of persistence up to 48 h. They also produced elevated levels of butyrate ranging from 5 to 14·85 mmol/l. To more effectively simulate conditions that prevail in different regions of the large intestine, a three-stage continuous culture cascade system was used to study further the fermentation of dextran, a low-molecular-mass oligodextran (IV) and maltodextrin. Oligodextran IV was shown to be the best substrate for bifidobacteria and lactobacilli with steady-state populations of bifidobacteria and lactobacilli being higher in all three vessels of the gut model than the respective populations resulting from dextran and maltodextrin. A maximum difference of 1·9 log was observed in vessel 1 for both bifidobacteria and lactobacilli in the case of dextran fermentation, while 1·4 log and 0·8 log in vessel 3 were the maximum differences for bifidobacteria and lactobacilli when maltodextrin was used as the carbohydrate source. Moreover, dextran and oligodextran appeared to stimulate butyrate production, with a maximum production up to 25·39 mmol/l in vessel 3 when fermenting dextran, followed by 21·70 mmol/l in the case of oligodextran IV and only 12·64 mmol/l in the case of maltodextrin.
- Published
- 2000
184. Colonic functional foods
- Author
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Robert A. Rastall, R. Fuller, Glenn Gibson, and H.R. Gaskins
- Subjects
Biology - Published
- 2000
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185. Synthesis of Homo- and Hetero-Oligosaccharides from Underivatized Sugars Using Glycosidases
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Christopher Bucke, Sony Suwasono, John Packwood, and Robert A. Rastall
- Subjects
Stereochemistry ,Chemistry ,Organic chemistry - Published
- 1999
- Full Text
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186. New Delivery Systems for Controlled Drug Release From Naturally Occurring Materials
- Author
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Nicholas Parris, LinShu Liu, Cunxian Song, V. Prasad Shastri, Weiliam Chen, Angela Kim, Mary Frame, Daniel Checkla, Yang-Hyun Yun, Paige Yellen, Philip Dehazya, Zengshe Liu, Sevim, Z. Erhan, Thomas Mckeon, Charlotta Turner, Sung-Tae Kang, Xiaohua He, Grace Chen, Jiann-Tsyh Lin, Jun Bae Lee, Hyun Jung Chung, Somlak Kongmuang, Tae Gwan Park, Arland T. Hotchkiss, Jeff Call, Peter Cooke, John B. Luchansky, Robert A. Rastall, Yasuhiko Tabata, Doo Sung Lee, Woo Sun Shim, Dai Phu Huynh, Eric M. Sussman, Ashwath Jayagopal, Frederick R. Haselton, Jie Huang, Peng Yao, Aijie Zhao, Chunshang Kang, Peiyu Pu, Jin Chang, Peter H. Cooke, Robert A. Moreau, Kevin B. Hicks, Zayniddin Muhidinov, Jamshed Bobokalonov, Reza Fassihi, Jin-Ye Wang, Hua-Jie Wang, Xin-Ming Liu, Xu Jin, Lanxia Liu, Lin Mei, Xigang Leng, Chao Zhang, Hongfan Sun, R.J. Levy, Joseph Kost, Marshall L. Fishman, Katerina Mastovska, Nicholas Parris, LinShu Liu, Cunxian Song, V. Prasad Shastri, Weiliam Chen, Angela Kim, Mary Frame, Daniel Checkla, Yang-Hyun Yun, Paige Yellen, Philip Dehazya, Zengshe Liu, Sevim, Z. Erhan, Thomas Mckeon, Charlotta Turner, Sung-Tae Kang, Xiaohua He, Grace Chen, Jiann-Tsyh Lin, Jun Bae Lee, Hyun Jung Chung, Somlak Kongmuang, Tae Gwan Park, Arland T. Hotchkiss, Jeff Call, Peter Cooke, John B. Luchansky, Robert A. Rastall, Yasuhiko Tabata, Doo Sung Lee, Woo Sun Shim, Dai Phu Huynh, Eric M. Sussman, Ashwath Jayagopal, Frederick R. Haselton, Jie Huang, Peng Yao, Aijie Zhao, Chunshang Kang, Peiyu Pu, Jin Chang, Peter H. Cooke, Robert A. Moreau, Kevin B. Hicks, Zayniddin Muhidinov, Jamshed Bobokalonov, Reza Fassihi, Jin-Ye Wang, Hua-Jie Wang, Xin-Ming Liu, Xu Jin, Lanxia Liu, Lin Mei, Xigang Leng, Chao Zhang, Hongfan Sun, R.J. Levy, Joseph Kost, Marshall L. Fishman, and Katerina Mastovska
- Subjects
- Drugs--Controlled release--Congresses
- Published
- 2008
187. Primary sequence analysis and representation techniques in carbohydrates
- Author
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Robert A. Rastall, Stephen Winter, Simon J. E. Taylor, J. Sykes, and Christopher Bucke
- Subjects
Statistics and Probability ,Computer science ,Molecular Sequence Data ,Protein primary structure ,Carbohydrates ,Sequence Homology ,Carbohydrate ,Biochemistry ,Computer Science Applications ,Computational Mathematics ,Computational Theory and Mathematics ,Carbohydrate Sequence ,Carbohydrate Conformation ,Molecule ,Primary sequence ,Molecular Biology ,Algorithm ,Sequence Analysis ,Algorithms ,Software - Abstract
Sequence similarity calculations of carbohydrates present several problems which must be addressed if a computer implementation is to be achieved. These problems range from the computational representation of the complex carbohydrate structrure to the method by which the comparison of residue and linkage is to be made. This paper therefore discusses the form of this representation and how two or more carbohydrates can be meaningfidly compared. An example set of results using this approach is presented and discussed to illustrate how similarity comparison can show relationships between carbohydrates, features that are otherwise hidden by the sheer volume of data which must be considered.
- Published
- 1993
188. The application of aqueous two-phase systems to oligosaccharide synthesis by alpha-mannosidase catalysed glycosyl transfer reactions
- Author
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Maxwell W. Adlard, Nicholas H. Rees, Christopher Bucke, Terence J. Bartlett, and Robert A. Rastall
- Subjects
Mannosidase ,General Chemical Engineering ,Molecular Sequence Data ,Oligosaccharides ,Polyethylene Glycols ,Inorganic Chemistry ,chemistry.chemical_compound ,alpha-Mannosidase ,PEG ratio ,Mannosidases ,Organic chemistry ,Glycosyl ,Glycosides ,Waste Management and Disposal ,chemistry.chemical_classification ,Aqueous solution ,Renewable Energy, Sustainability and the Environment ,Organic Chemistry ,Water ,Dextrans ,Oligosaccharide ,Pollution ,Kinetics ,Fuel Technology ,Dextran ,Enzyme ,chemistry ,Carbohydrate Sequence ,Solubility ,Evaluation Studies as Topic ,Yield (chemistry) ,Biotechnology - Abstract
Aqueous two-phase systems formed from PEG and dextran have been applied to the synthesis of oligosaccharide by Jack bean alpha-mannosidase in reverse. Whilst rates of synthesis and percentage yields were similar in two-phase systems and one-phase aqueous buffer systems, a ten-fold increase in yield of product per unit of enzyme was seen. In addition, the use of aqueous two-phase systems offers potential process advantages over one-phase systems for the synthesis of oligosaccharides.
- Published
- 1992
189. Oligosaccharides in Food and Agriculture
- Author
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Gillian Eggleston, Gregory L. Côté, Jeffery S. Rohrer, Casey C. Grimm, Deborah A. Grimm, Christine J. Bergman, Robert A. Rastall, Arland T. Hotchkiss, Estibaliz Olano-Martin, William E. Grace, Glenn R. Gibson, Kiaus Buchholz, Juergen Seibel, Scott M. Holt, Candace Miller-Fosmore, Magali Remaud-Simeon, Cècile Albenne, Gilles Joucia, Emeline Fabre, Sophie Bozonnet, Sandra Pizzut, Pierre Escalier, Gabrielle Potocki-Vèronèse, Pierre Monsan, Tetsuya Nakada, Tomayaki Nishimoto, Hiroto Chaen, Shigeharu Fukuda, Bryan W. Wolf, JoMay Chow, Maureen K. Snowden, Keith A. Garleb, Bryan C. Tungland, James A. Douglas, Merilyn Manley-Harris, John J.C. Scheffer, Natalie A. Wong, John F. Robyt, Kwan Hwa Park, Soo-Bok Lee, Seung-Heon Yoon, Frank Barresi, Angela Eads, Melanie Keuyon, P.G. Morel du Boil, Michael Grisham, Gillian Eggleston, Gregory L. Côté, Jeffery S. Rohrer, Casey C. Grimm, Deborah A. Grimm, Christine J. Bergman, Robert A. Rastall, Arland T. Hotchkiss, Estibaliz Olano-Martin, William E. Grace, Glenn R. Gibson, Kiaus Buchholz, Juergen Seibel, Scott M. Holt, Candace Miller-Fosmore, Magali Remaud-Simeon, Cècile Albenne, Gilles Joucia, Emeline Fabre, Sophie Bozonnet, Sandra Pizzut, Pierre Escalier, Gabrielle Potocki-Vèronèse, Pierre Monsan, Tetsuya Nakada, Tomayaki Nishimoto, Hiroto Chaen, Shigeharu Fukuda, Bryan W. Wolf, JoMay Chow, Maureen K. Snowden, Keith A. Garleb, Bryan C. Tungland, James A. Douglas, Merilyn Manley-Harris, John J.C. Scheffer, Natalie A. Wong, John F. Robyt, Kwan Hwa Park, Soo-Bok Lee, Seung-Heon Yoon, Frank Barresi, Angela Eads, Melanie Keuyon, P.G. Morel du Boil, and Michael Grisham
- Published
- 2003
190. Dietary modulation of the human colonic microbiota: updating the concept of prebiotics.
- Author
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Glenn R. Gibson, Hollie M. Probert, Jan Van Loo, Robert A. Rastall, and Marcel B. Roberfroid
- Subjects
PROBIOTICS ,DIETARY supplements ,GUT microbiome ,BIFIDOBACTERIUM - Abstract
Prebiotics are non-digestible (by the host) food ingredients that have a beneficial effect through their selective metabolism in the intestinal tract. Key to this is the specificity of microbial changes. The present paper reviews the concept in terms of three criteria: (a) resistance to gastric acidity, hydrolysis by mammalian enzymes and gastrointestinal absorption; (b) fermentation by intestinal microflora; (c) selective stimulation of the growth and/or activity of intestinal bacteria associated with health and wellbeing. The conclusion is that prebiotics that currently fulfil these three criteria are fructo-oligosaccharides, galacto-oligosaccharides and lactulose, although promise does exist with several other dietary carbohydrates. Given the range of food vehicles that may be fortified by prebiotics, their ability to confer positive microflora changes and the health aspects that may accrue, it is important that robust technologies to assay functionality are used. This would include a molecular-based approach to determine flora changes. The future use of prebiotics may allow species-level changes in the microbiota, an extrapolation into genera other than the bifidobacteria and lactobacilli, and allow preferential use in disease-prone areas of the body. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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191. Metallogenetic zones
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Robert Heron Rastall
- Subjects
Geophysics ,Geochemistry and Petrology ,Economic Geology ,Geology - Published
- 1923
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192. The Geology of the Districts of Worcester, Robertson, and Ashton (Cape Colony)
- Author
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Robert Heron Rastall
- Subjects
Cape ,Geological survey ,Subject (documents) ,Geologic map ,Original research ,Archaeology ,Geology - Abstract
I. Introduction and Bibliography. During the Long Vacation of 1910 I was enabled to pay a visit to South Africa, partly for the purpose of making collections for the Sedgwick Museum at Cambridge, and partly for original research in South African geology. Acting chiefly on the advice of Dr. A. W. Rogers, the head of the Geological Survey of Cape Colony, I undertook the investigation of the neighbourhood of the towns of Worcester, Robertson, and Ashton, in the Western Province of Cape Colony. Owing to special conditions, the geology of this district comprises some features of exceptional interest, and the elucidation of the problems there presented would cast valuable light on several obscure features of the geological history of the country as a whole. The most important of these problems refers to the origin and age of the Worcester-Swellendam Fault, one of the greatest dislocations of its kind with which we are acquainted. This forms the principal subject of the following paper; but several other questions are dealt with in considerable detail, especially the lithological character and structure of the Malmesbury Series, the oldest rocks of this part of the Colony—a subject on which hitherto little work has been done. Incidental reference is made to other points bearing on the principal objects of the investigation. The district is comprised in Sheets 1, 2, and 4 of the geological map, on the scale of about 33/4 miles to the inch, issued by the Geological Commission of the Cape of Good Hope
- Published
- 1911
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193. Petrographical Notes on the Stockdale Shales
- Author
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Robert Heron Rastall
- Subjects
chemistry.chemical_compound ,chemistry ,Streak ,Carbonate ,chemistry.chemical_element ,Mineralogy ,Mica ,Texture (geology) ,Quartz ,Carbon ,Oil shale ,Chlorite ,Geology - Abstract
A. Atrypa-flexuosa Zone, Skelgill.This consists in part of finely-divided micaceous material, with chlorite of the usual type, and some quartz, but there is also a considerable amount of carbonate, and the rock effervesces freely with cold dilute acid. It differs therefore notably from the others, and may be described as an impure limestone [20,008]. B.Green Streak, Argenteus Zone, Skelgill (with parts of adjoining graptolitic mud-bands).This specimen shows very pronounced colour-banding. The pale greenish-grey ‘streak’ is strongly differentiated from the other part, which is dark-grey. On ignition for 30 minutes, the ‘green streak’ becomes somewhat paler, nearly white; and the dark bands are reddened.Under the microscope the ‘green streak’ is seen to be closely similar to the Browgill Shale (G, p. 132), though of somewhat finer texture, and with much more pronounced orientation of the flakes of mica and chlorite. Grains of quartz determinable under a half-inch objective are quite rare.The dark rock enclosing the streak, which belongs to the graptolitic bands, appears to be essentially of the same composition, although the structure is partly obscured by the presence of a large amount of dark brownish-black material. Since this reddens on ignition, it is probably in part ferrous sulphide and in part carbon [20,006]. C.Green Streak, Pont ErwydThis is quite similar in composition and general character to the ‘green streak’ from Skelgill, but slightly coarser in texture: very angular fragments of quartz are easily visible incertain bands.The Rock
- Published
- 1925
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194. On the Boulders of the Cambridge Drift: their Distribution and Origin
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Robert Heron Rastall and James Romanes
- Subjects
business.industry ,Short paper ,Distribution (economics) ,Club ,Glacial period ,business ,Archaeology ,Geology - Abstract
I. Introduction. The origin and distribution of the boulders of the Glacial Drift of Cambridgeshire and the adjoining countries is a subject of great interest on which hitherto little work has been done. Although much has been written on the Glacial deposits of this district as a whole, little attempt has been made to examine in detail the types of rock represented in the Boulder-Clay and to trace them to their sources. During the last seven or eight years a large amount of material has been collected, both by the members of the Sedgwick Club and by other independent workers. A brief account of some of the results obtained up to that time was given by Mr. Fearnsides in the official hand-book compiled for the Cambridge meeting of the British Association in 1904, and a short paper entitled ‘On Boulders from the Cambridge Drift, collected by the Sedgwick Club’ was published in the same year by one of the present authors. Since that date much new material has been collected, and the whole has now come into our hands. The additional evidence thus made available, shows that the conclusions set tbrth in the previous publications can be considerably extended. The total number of boulders collected now amounts to many hundreds ; and, as naturally would be expected, a great number of them, perhaps the majority, are of uncertain origin, since it, is clear that the field of derivation is a very wide one. However, a large number of rock-types have
- Published
- 1909
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195. The Buttermere and Ennerdale Granophyre
- Author
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Robert Heron Rastall
- Subjects
Volcanic rock ,Paleontology ,Intrusion ,geography ,Igneous rock ,geography.geographical_feature_category ,Fell ,computer ,Geology ,Pike ,computer.programming_language ,Mile - Abstract
I. Introduction In the western part of the English Lake-District there occurs a large development of igneous rocks, which are conveniently described, collectively, as the Buttermere and Ennerdale Granophyre. This group extends for nearly 10 miles from north to south, and for nearly 5 miles from east to west. In this large area are to be found several different rock-types, which present many features of interest; and, at the suggestion of Dr. J. E. Marr, F.R.S., I have undertaken the investigation of the phenomena shown in this district. The first and only detailed description of this rock-mass was given by Clifton Ward nearly 30 years ago; and the subject has apparently never been touched as a whole by modern methods, although Mr. Alfred Harker has published a short description of some specimens from the Wastwater district. The map (fig. 1, p. 254) shows that the exposure of this group of rocks is very irregular in form: to the west of Buttermere is a somewhat lenticular mass about 2 1/2 miles long by nearly a mile wide, forming the lower part of High Stile, and the main mass of Red Pike and Gale Fell. The southern boundary of this intrusion cuts across the summit of Red Pike; and there is a strong contrast between the rugged crags of High Stile, formed of volcanic rocks of the Borrowdale Series, and the smooth outlines given by the intrusive rocks of Red Pike. This intrusion is connected with a much larger
- Published
- 1906
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196. Continuous production of oligodextrans via controlled hydrolysis of dextran in an enzyme membrane reactor
- Author
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Robert A. Rastall, K.C. Mountzouris, and Steven G. Gilmour
- Subjects
Hydrolysis ,Chromatography ,Membrane reactor ,Chemistry ,Enzymatic hydrolysis ,Yield (chemistry) ,Dextrose equivalent ,Continuous stirred-tank reactor ,Steady state (chemistry) ,Response surface methodology ,Food Science - Abstract
The continuous production of oligodextrans was investigated via the enzymatic hydrolysis of industrial grade dextran using an endodextranase. A recycle continuous stirred tank (CSTR) membrane reactor system was employed to provide the means of controlling oligodextran physicochemical characteristics. Response surface methodology (RSM) and a central componsite statistical experimental design were used to assess the effects of substrate concentration (20 to 50 g dm 2 ), enzyme concentration (6250 to 62500 U dm 2 ), and residence time (60 to 120 min) in the reactor on the yield, dextrose equivalent (DE), and oligesaccharide content of the products. The reactor system was operated at steady state, generally obtained within 60 to 120 min from reactor start-up. Oligodextran yields ranged from 84.4% to 98.7%, DE values ranged from 22 to 41, and oligosaccharide content ranged from 55.9% to 93.4 % (w w 2 ). The reactor produced 3 types of oligodextran products, with respect to their polysaccharide content: (a) 30% and < 44%, Oligodextran molecular weight distributions were mainly within the molecular weight cut-off (MWCO) of 10 kDa of the membrane used.
197. In vitro investigation into the potential prebiotic activity of honey oligosaccharides
- Author
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Robert A. Rastall, Glenn R. Gibson, María Luz Sanz, Valle Morales, Nieves Corzo, Alexandra Drakoularakou, and Nikolaos Polemis
- Subjects
Chromatography, Gas ,medicine.medical_treatment ,Oligosaccharides ,Biology ,chemistry.chemical_compound ,Feces ,Lactobacillus ,medicine ,Monosaccharide ,Food science ,chemistry.chemical_classification ,Bacteria ,Prebiotic ,Fructooligosaccharide ,Probiotics ,digestive, oral, and skin physiology ,food and beverages ,Fructose ,General Chemistry ,Honey ,Oligosaccharide ,biology.organism_classification ,Yeast ,chemistry ,Biochemistry ,Fermentation ,Bifidobacterium ,General Agricultural and Biological Sciences - Abstract
The effect of honey oligosaccharides on the growth of fecal bacteria was studied using an in vitro fermentation system. Prior to treatment, glucose and fructose (31.73 and 21.41 g/100 g of product, respectively) present in honey, which would be digested in the upper gut, were removed to avoid any influence on bacterial populations in the fermentations. Nanofiltration, yeast (Saccharomyces cerevisiae) treatment, and adsorption onto activated charcoal were used to remove monosaccharides. Prebiotic (microbial fermentation) activities of the three honey oligosaccharide fractions and the honey sample were studied and compared with fructooligosaccharide (FOS), using 1% (w/v) fecal bacteria in an in vitro fermentation system (10 mg of carbohydrate, 1.0 mL of basal medium). A prebiotic index (PI) was calculated for each carbohydrate source. Honey oligosaccharides seem to present potential prebiotic activity (PI values between 3.38 and 4.24), increasing the populations of bifidobacteria and lactobacilli, although not to the levels of FOS (PI of 6.89).
198. In vitro fermentation by human fecal microflora of wheat arabinoxylans
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Robert A. Rastall, Simon A. Hughes, L Li, Glenn R. Gibson, Peter R. Shewry, and María Luz Sanz
- Subjects
Adult ,Male ,Colon ,medicine.medical_treatment ,Inulin ,Biology ,Polysaccharide ,Butyric acid ,chemistry.chemical_compound ,Feces ,Arabinoxylan ,medicine ,Humans ,Lactic Acid ,In Situ Hybridization, Fluorescence ,Triticum ,chemistry.chemical_classification ,Prebiotic ,Short-chain fatty acid ,food and beverages ,General Chemistry ,Fatty Acids, Volatile ,Lactic acid ,chemistry ,Biochemistry ,Fermentation ,Female ,Xylans ,General Agricultural and Biological Sciences - Abstract
The fermentation of three arabinoxylan (AX) fractions from wheat by the human fecal microflora was investigated in vitro. Three AX fractions, with average molecular masses of 354, 278, and 66 kDa, were incorporated into miniature-scale batch cultures (with inulin as a positive prebiotic control) with feces from three healthy donors, aged 23-29. Microflora changes were monitored by the culture-independent technique, fluorescent in situ hybridization, and short chain fatty acid (SCFA) and lactic acid production were measured by high-performance liquid chromatography. Total cell numbers increased significantly in all treated cultures, and the fermentation of AX was associated with a proliferation of the bifidobacteria, lactobacilli, and eubacteria groups. Smaller but statistically significant increases in bacteroides and clostridia groups were also observed. All AX fractions had comparable bifidogenic impacts on the microflora at 5 and 12 h, but the 66 kDa AX was particularly selective for lactobacilli. Eubacteria increased significantly on all AX fractions, particularly on 66 kDa AX. As previously reported, inulin gave a selective increase in bifidobacteria. All supplemented cultures showed significant rises in total SCFA production, with a particularly high proportion of butyric acid being produced from AX fermentation. The prebiotic effect, that is, the selectivity of AX for bifidobacteria and lactobacilli groups, increased as the molecular mass of the AX decreased. This suggests that molecular mass may influence the fermentation of AX in the colon.
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199. Food for thought! Inulin-type fructans: Does the food matrix matter?
- Author
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Peter Philip James Jackson, Anisha Wijeyesekera, Stephan Theis, Jessica van Harsselaar, and Robert Adrian Rastall
- Subjects
Inulin: Inulin-type fructans ,Prebiotics ,Carbohydrates ,Food processing ,Gut microbiota ,Food matrices ,Nutrition. Foods and food supply ,TX341-641 - Abstract
Food matrices can be described as the final composition of a food product which results from complex interactions between compounds found within different ingredients and the processing parameters used in production. These factors, not only impact on the final structure of a product, but also have the potential to alter both the structural integrity and bioavailability of potentially beneficial compounds present, for example, dietary fibres. As a result, there is growing curiosity amongst the scientific community on whether the food matrix may impact on the prebiotic efficacy of inulin-type fructans. Therefore, the purpose of this review is to explore previous food-based inulin-type fructan supplementation studies to determine whether the food matrix directly impacts on their prebiotic efficacy. Our working hypothesis is that other potentially prebiotic ingredients and components present within the food may alter inulin-type fructans prebiotic effect.
- Published
- 2022
- Full Text
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