Effect of heat-moisture treatment on physicochemical properties of white sorghum starch

White sorghum starch was subjected to heat-moisture treatment (HMT) at moisture levels ranging from 18% to 27%. The treatments had a great impact on the physicochemical properties as studied with a rapid visco analyzer (RVA). The increase in onset temperature of viscosity development and the decrease in the peak viscosity observed with RVA as a consequence of HMTs were also attributed to the decrease in swelling power and solubility. The swelling power and solubility increased with increasing degree of alkalinity which revealed that they were pH dependent with higher values obtained at pH 12 in both native and modified starches. Water absorption capacity, oil absorption capacity and alkaline water retention of the starches were enhanced after HMT.