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Physico‐Chemical Properties and the Degradation of Oat Bran Polysaccharides in the Gut of Pigs
Author(s) -
Johansen Helle N,
Bach Knudsen Knud Erik,
Wood Peter J,
Fulcher R Gary
Publication year - 1997
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/(sici)1097-0010(199701)73:1<81::aid-jsfa695>3.0.co;2-z
Subject(s) - bran , caecum , polysaccharide , starch , small intestine , food science , arabinoxylan , ileum , gastrointestinal tract , chemistry , avena , stomach , glucan , large intestine , solubility , biochemistry , biology , botany , medicine , raw material , organic chemistry
Physico‐chemical properties and the digestibility of carbohydrates (starch, β‐glucan and arabinoxylan (AX)) were studied in the gastrointestinal contents of pigs fed diets based on oat bran. One diet was made of commercially prepared oat bran and another of oat bran milled to pass a 1 mm screen. The pigs were slaughtered and samples were collected quantitatively from 10 sites of the gastrointestinal tract either 1 or 3 h after the morning feeding. The viscosity of the liquid phase (obtained by centrifugation) of the stomach and small intestinal contents varied greatly between animals, and was not significantly different between segments of the upper gastrointestinal tract. The molecular weight of β‐glucan was reduced up to 20‐fold in the upper gastrointestinal tract but was of a relatively low digestibility until the terminal ileum. The solubility (the fraction of the total content in the liquid phase of digesta after centrifugation) of β‐glucan varied from 0·25 to 0·58 in the stomach and small intestine, whereas the solubility of AX was in the range of 0·04–0·16. Microscopic examination of digesta showed that β‐glucan was retained in intact endospermic cell wall structures, which remained evident until the distal small intestine but was completely disrupted in the caecum. In spite of a cumulative digestibility of non‐starch polysaccharides and AX of ∽0·90 in the large intestine, identifiable fragments of aleurone cell walls resistant to complete microbial degradation remained. © 1997 SCI.