Relationship between temperature during ripening period, appearance quality of polished rice, alpha-amylase activity, rice taste and viscoelasticity

In this study, we investigated the effects of temperature during the ripening period (August temperatures in the production area) on the appearance quality, enzyme activity, taste, and viscoelasticity of rice produced using the "Koshihikari" rice cultivar. (1) The percentage of cracked and broken grains increased with increase in temperature during the ripening period. (2) A positive correlation was found between alpha-amylase activity and the ratio of immature white grains (r=0.92). (3) The taste and hardness decreased with an increase in temperature during the ripening period.