Understanding the mechanisms of ß-glucan regulating the in vitro starch digestibility of highland barley starch under spray drying: Structure and physicochemical properties.

ABSTRACT

This study investigated the effects of ß-glucan (0-6%) on the physicochemical properties, structure, and in vitro digestibility of highland barley starch (HBS) under spray drying (SD). SD significantly enhanced the inhibitory effect of 6% ß-glucan on the in vitro digestibility and glucose diffusion of HBS. After SD, the addition of ß-glucan at 4% and 6% concentration significantly increased the pasting temperatures of starch while decreased the rheological properties. Thermal properties demonstrated that ß-glucan improved the thermal stability and residue content of HBS at 600°C, lowered its maximum loss rate, and maintained its thermal stability after SD. Structural properties showed that ß-glucan affected greatly on amorphous regions of HBS after SD. Additionally, ß-glucan dispersed more evenly in the starch system and experienced hydrogen bonding with starch after SD. This study presents a novel approach to enhancing the inhibitory effect of ß-glucan on starch digestion.