Effects of Heat Shock Treatment on Rice Quality during Storage (Part 2)
— Nutritional and Pasting Properties Changes —

Abstract

Heat shock treatments (HSTs) using microwave radiation were performed on harvested rice (cv. Koshihikari) up to 60, 70 and 80°C, and kept additionally for 0, 1 and 3 min, following drying and storage at 40°C for 6 months. For control rice, during storage there was a decrease in protein and starch digestibility, increase in setback viscosity (SV), final viscosity (FV) and pasting temperature (PT), while peak viscosity (PV) increased rapidly for the first 2 months then decreased. The HSTs at 70 and 80°C were effective in maintaining a high value of starch digestibility and low value of PV during storage, while the HSTs at 60°C retarded changes of PV and FV values. The results showed that HST would benefit quality maintenance of stored rice.