Comparison of the effect of ultrasound and microwave on the functional properties and in vitro digestibility of normal maize starch and potato starch

Abstract This study aimed to compare the effects of ultrasound and microwave, single or dual treatments, on the functional and in vitro digestive properties of normal maize starch and potato starch. The solubility, water and oil absorption capacity, and the freeze–thaw stability of both starches increased after treatment, and these functional properties of potato starch negatively correlated with relative crystallinity and positively correlated with damaged starch content. Meanwhile, the dual modification sequence showed a significant effect on the solubility, syneresis, and in vitro digestibility of potato starch. Under the single treatment of microwave, the content of resistant starch increased while that of rapidly digestible starch decreased, which might be due to the formation of the amylose–lipid complex by microwave treatment. However, the ultrasound treatment and dual treatment increased the starch digestibility, probably due to the loosening of the internal structure of starch by ultrasound. The utilization of dual ultrasound and microwave modification showed a prospective industrial application in the modification of starch. Practical applications Ultrasound and microwave treatment, single or dual, have been widely used to study their effects on the physicochemical properties of starch. However, there is little information on the comparison of functional properties and in vitro digestibility of maize starch (A‐type crystalline) and potato starch (B‐type) by dual modification of ultrasound and microwave. The results showed that the functional properties of both starches improved after treatment, and the dual modification sequence showed a significant effect. The in vitro digestibility of starch decreased after microwave treatment, but increased after ultrasound treatment and dual treatment. We believe that the food industry can utilize the results of this study in the modification of starch with specific functional properties.