Abstract: The high amylose maize starch granules were modified by the microwave and their digestion resistibility was changed under different moisture mass percents, microwave temperatures, treatment time and powers. The granule appearance and digestion resistibility of native and microwave modified high amylose starch granules under different microwave conditions were investigated by SEM and in in vitro digestion model. It was found that the microwave modified starch granule surface became roughness and most of them were damaged to some little fragment when the resistant starch content reached 22.0%. The results showed that under the microwave filed the moisture mass percent and microwave temperature had significant effects on the high amylase maize starch digestion resistibility but the microwave power and time had little effect.

Key words: microwave modification, high amylose maize starch, granule appearance, digestion resistibility