Structure and functionality of micronized maize starch differing in amylose content

Abstract

In this study, the effects of micronization on starch structure and properties were analyzed. Waxy maize starch (MS1), normal maize starch (MS2), high-amylose starch (MS3), and Gelose 80 (MS4), underwent micronization via jet milling. Results revealed that MS1 exhibited the most significant particle size reduction (20.04 to 6.72 μm) post-micronization among the four starch types, while MS4 showed the least decrease (12.71 to 9.86 μm). As micronization increased, content amylose rose, accompanied by decreases in lipid and protein content, molecular weight, and crystallinity. The gelatinization temperature, apparent viscosity, and hydrolysis rate of starch are reduced by micronization, but the swelling power is increased. Starches with higher amylose content are more resistant to mechanical force. Correlation analysis showed amylose content had a stronger influence on hydrolysis rate than particle size. This study underscores jet milling as a promising physical method for producing customized starch raw for the food industries.