In Vitro α-Amylase Hydrolysis of Modified Starch and Postprandal Plasma Glucose Response

Abstract

Seven kinds of gelatinized modified starch were compared for their effects on postprandial plasma glucose response in rats and their α-amylase hydrolysis in Vitro. The modified starches used in this study were oxidized starch (PO) and hydroxypropyl distarch phosphate (PHP-I and -II) prepared from potato starch, and roast dextrin (CD), acetylated distarch phosphate (CA) and hydroxypropyl distarch phosphate (CHP-I and -II) prepared from corn starch. Using a stomach tube, rats were given 100mg of modified starch per 100g body weight as a 10% (w/v) solution. CD elicited a greater plasma glucose response than PO, CA, PHF-I, II and CHP-I, II. The digestibility by α-amylase in the first stage for 30min was as follows: CD>PO>CA>CHP I and PHP I, II>CHP II. The viscosities of CD and PO were markedly lower than those of CA, PHP-I, II and CHP-I, II. Therefore, digestibility and viscosity seem to be factors determining the difference in postprandial plasma glucose response between these modified starches.