Effect of Multiple Short-Time Repeated Microwave Treatments on the Structure and Physicochemical Properties of Sweet Potato Starch

The effects of short-time repeat microwave treatments on the physicochemical properties of sweet potato starch are investigated in this study. Pores appear on the surface of starch after repeat microwaves treatment, and the repeat microwave treatment for 60 s has a greater effect on the destruction of the pore size of the starch surface. Compared with the native starch, the Fourier infrared spectrum of short-time repeat microwave treatment shows no new peaks but reduces the short-range ordering of the starch. The short-time repeat microwave treatment has no effect on the crystal mode of starch (A-type), but the relative crystallinity of starch decreases. Multiple short-time repeat microwave treatments reduce the peak viscosity of starch, but increase the water/oil holding capacity (WHC/OHC) and the particle diameter of starch. Modified starch obtained by short-time repeat microwave treatment can be used as thickener.