The aim of this study was to use a low commercial value by-product of the oil palm industry as an oligosaccharide source, identifying in the process those molecular weights that would have the highest prebiotic efficacy. Oil palm empty fruit bunches (OPEFB) fibre were subjected to autohydrolysis to obtain oligosaccharide-rich liquor. The processed liquor was characterised to determine the operational conditions required to produce the highest xylooligosaccharide (XOS) concentration. Two different purification techniques were employed to remove the monosaccharides and non-saccharide compounds present in the liquor: gel filtration chromatography (GFC) and sequential charcoal adsorption and ultrafiltration. With GFC purification, six mixed XOS fractions with different average degree of polymer is at ion (avDP 4, 7,14,28,44,64) were obtained. The effect of avDP on the human faecal microbiota was determined in vitro, in pH controlled batch cultures using XOS as the main carbohydrate source. The most favourable fermentation profiles were observed with the lower avDP fractions (4, 7, and 14) which showed the highest selectivity for bifidobacteria. A broader DP distribution of XOS fraction with an avDP 9, obtained through ultrafiltration, was further tested in a three stage continuous culture system. The findings suggest that XOS is a potential prebiotic that combines the benefits of increasing health-associated bacteria in the vessel 3 of the model system that simulates the distal colon and reducing proteolysis therein with butyrate production, a metabolite that plays a central role in the regulation of colonic cell proliferation, differentiation and modulation of gene expression.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:632859 |
| Date | January 2013 |
| Creators | Ho, Ai Ling |
| Publisher | University of Reading |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
Page generated in 0.0015 seconds