Abstract:After studying the formation of complexes between the main monomers of phenols (ferulic acid, gallic acid) in rice and rice starch, the effects of polyphenols on the acitivity of α-amylase and glucosidase were investigated, as well as the release characteristics of polyphenols in the complex under different conditions. The results showed that under the action of α-amylase, the hydrolysis rate of starch decreased with an increase of polyphenol content in the complex from 5% to 20% (ferulic acid group decreased from 54% to 49.69%, gallic acid group decreased from 57.97% to 49.81%). Similarly, under the action of glucosidase, the hydrolysis rate of gallic acid decreased significantly from 65.72% to 57.13%. Regarding digestion characteristics, the addition of gallic acid involving different addition amounts (from 5% to 20%) significantly reduced the content of RDS from 80.76% to 64.62%, the SDS content of ferulic acid decreased (from 15.69% to 14.07%), and the RS content increased significantly from 11.26% to 16.69%. The release of ferulic acid by the complex increased by 131.43% with an increase in temperature of the aqueous solution (30~80 ℃). With increased pH values (2~6), the release of ferulic acid exhibited a trend of first decreasing and then increasing, while the release of gallic acid displayed an increasing trend. In simulated gastrointestinal digestion experiments, it was found that ferulic acid was released in advance in gastric juice, while the release of gallic acid (5%) in intestinal juice decreased from 2.19 mg to 1.56 mg. These results provide a theoretical reference for the application of dietary polyphenols in starch-based functional foods.
