Effects of high-voltage electric field treatment on physicochemical properties of potato starch

The application of a high-voltage electric field (HVEF) is a novel method for starch. First, potato starch slurry (20%, w/w) were subject to HVEF treatment at 10, 20, 30 and 40 kV, and the treatment time was 10, 20, 30, 40, 50 min respectively. Then, the modified starch was characterized by using X-ray diffraction (XRD), Fourier transformation infrared (FT-IR) spectroscopy, pasting behavior, water absorption capacity (WAC), light transmission and scanning electron microscopy (SEM). The results showed that HVEF caused a shift in the gelatinization range to lower temperatures, and a decrease in solubility, swelling power and crystallinity. HVEF was evidenced to change WAC and Light transmittance, with a tendence firstly increase and then decrease with the increasing of the treatment time. The SEM micrographs demonstrated that some roughness or damages emerged on the surface of potato starch granules after HVEF treatments. The X-ray diffraction showed that the decrease of crystallinity during the HVEF treatment. It was concluded that HVEF destroyed amorphous area and surface crystalline zone of starch.