Importance of oat bran beta-glucan solubility in dose response GI study

摘要

Soluble fiber such as oat beta-glucan lowers postprandial glucose and insulin levels. It is important that the fiber is soluble and can increase viscosity. Only soluble and viscose fibers are able to increase the viscosity of gastrointestinal content.In this work a GI-dose response was tested using high beta-glucan oat bran. Oat bran was served to healthy subjects as a drink. Three levels of oat bran (2, 4 and 6 g beta-glucan) were mixed individually to glucose solution leading to 50g available carbohydrate servings. The extractability and viscosity of soluble fiber in the drinks were measured after soluble fibre extraction. The extractability of beta-glucan in oat bran drinks had a high correlation with GI values. The viscosity of soluble fibre was identical in drinks. The results showed that the drink with highest percentage of soluble beta-glucan lowered most the postprandial glucose and insulin peaks. This study showed that the amount of extractable fiber was the most important factor in GI dose response study.