Amylopectin content rather than amylose or protein content is critical to determining the starch digestion rate in high-amylose rice

Abstract

The starch digestion properties of cooked rice are associated with the chemical compositions of the rice grain. However, limited information is available on the chemical composition governing starch digestion properties in high-amylose rice. To overcome this knowledge gap, correlation plot analysis and partial correlation analysis were utilized to assess the correlations between active digestion duration, total glucose production, and glucose production rate of cooked rice to amylose, amylopectin, and protein content of rice grains throughout 17 high-amylose varieties. The correlation plot analysis identified significant positive or negative linkages between total glucose production and the glucose production rate of cooked rice with grain amylose, amylopectin, and protein content. Nevertheless, partial correlation analysis only characterized a significant positive correlation between glucose production rate and grain amylopectin content. The findings of this study indicate that grain amylopectin content rather than grain amylose or protein content is critical for the determination of the rate of starch digestion in high-amylose rice.