Abstract:To study the effect of different temperature of autoclaving on the granule structure and digestibility of starch with three different crystal forms (type A, type B, and type C) were investigated. Starch from corn, potato and pea were processed at 110 ℃, 120 ℃, and 130 ℃, respectively, and their physicochemical properties and digestibility before and after treatment were characterized by XRD, SEM, RVA, DSC and enzymatic hydrolysis. Results indicated that the gelatinization characteristics of starch changed significantly after autoclaving. The peak viscosity, recovery value, final viscosity and disintegration value decreased, while the gelatinization temperature increased. Microstructural analysis showed that moisture and thermal energy during autoclaving resulted in partial gelatinization of starch granules, and subsequently resulting in surface cavity on the granules. After autoclaving, the potato starch gradually lost the characteristic diffraction peak of type B crystal, while that of type A crystal appeared. Compared with the original pea starch, the crystal form of pea starch after autoclaving tended to change from type C to type A, however, the diffraction peaks of corn starch insignificantly changed. In addition, the content of resistant starch in different crystalline starch after autoclaving significantly increased(p<0.05). This study systematically revealed the changes in the structure and digestibility of different crystalline starches after autoclaving, providing a theoretical basis for the subsequent preparation of starch-based foods with lower digestion
