Microwave-Induced Modification in Physical and Functional Characteristics and Antioxidant Potential ofNelumbo nuciferaRhizome Starch

The microwave-induced modifications in physical characteristics, functional properties, and antioxidant potential ofNelumbo nuciferarhizome starch were studied. The rhizome flour was subjected to microwave irradiation at different treatment times (1, 2, 3, 4 and 5 min) at the low-medium intensity (200 W). The starch was obtained from the native and microwave treated flour and analyzed for its physical characteristics, functional properties, and antioxidant potential. The microwave treatment showed a significant (p < 0.05) decrease in total starch yield and oil holding, swelling, and iron-binding capacity of the starch. Microwave treatment resulted in disruption of morphology and conversion of C-type crystalline structure to C(A)and C-B-type structures of starch. The variations in antioxidant properties of starch were associated with the microwave-induced modification in the structure and physical characteristics of starch. A significant time-dependent increase in the content of reducing monosaccharides, Trolox equivalent total antioxidant activity, and free radical scavenging capacity was observed in microwave treated starch. The data may be a valuable contribution to the literature regarding microwave-induced modification in physical, functional and antioxidant properties of lotus rhizome starch.