Gastrointestinal release of beta-glucan and pectin using an in vitro method.

摘要

The release of soluble dietary fibre is a prerequisite for viscous effects and hence beneficial health properties. A simple in vitro method was adapted to follow the release during gastrointestinal digestion, and the percentage of solubilized fibre was measured over time. beta-Glucan from oat bran was mainly released during gastric digestion, while the release of pectin from sugar beet fibre continued in the small intestine. Unmilled fractions of sugar beet fibre released more soluble fibre than oat bran flakes, probably due to the porous structure of sugar beet fibre as a result of manufacturing processes, but also due to differences in source. Milling to smaller fibre particles significantly improved releasability (from 20 to 55% released beta-glucan and from 50 to 70% released pectin, respectively, after digestion). When milled fibres were included in individual food matrices, the release was reduced by protein and starch matrices (5% beta-glucan and 35% pectin released, respectively) and slowed by fat (45% beta-glucan and 60% pectin released). This may result in a too low or too late release in the upper small intestine to be able to interfere with macronutrient uptake. It is suggested that the method may be suitable for predicting the gastrointestinal release of soluble dietary fibres from food matrices in the development of healthy food products.