Physicochemical properties of modified sweet potato starch through heat moisture treatment

The research was aimed to study the physicochemical properties of modified sweet potato starch through heat moisture treatment (HMT). The treatment which was carried out in this research was the different durations of HMT (1, 2, and 3 h at 110 °C). The modified sweet potato starch were characterized by moisture content, solubility, swelling volume, pasting properties, X-ray diffraction, and morphological properties. The result showed that HMT reduced moisture content, solubility, and swelling volume of sweet potato starch. HMT increased setback viscosity, final viscosity, and pasting temperature, however decreased peak viscosity and breakdown viscosity of sweet potato starch. The longer HMT duration decreased moisture content, solubility, and swelling volume of sweet potato starch. Modified sweet potato satrch showed higher crystallinity than that of the native sweet potato starch. The surface structural characteristics of modified sweet potato starch were either round or polygonal and some hollow on the surface. The modified sweet potato starch by HMT increases gelatinization transition temperatures and thermal stability and reduces the granular swelling and solubility. These results suggested that sweet potato starches modified by HMT shows a promising future for exploration as packaging material or suitable for starch noodle production.