Changes in mean air temperature after heading and starch characteristics of rice grains for sake making among harvest years and areas

The relationship between mean air temperature after heading and starch characteristics of rice grains, which correlated with enzyme digestibility of steamed rice grains, was investigated. It was confirmed that the diff erence in the temperature during grain fi lling was the main factor for the variation in digestibility of steamed rice grains among harvest areas even within the same rice cultivar. When the mean air temperatures during one month after heading were higher, twenty-fi ve rice cultivars for sake making showed higher gelatinization temperatures measured by diff erential scanning calorimetry(DSC). Previously, we reported that, when the gelatinization temperature was higher, the enzyme digestibility of steamed rice grains was lower. Therefore, from the previous and present studies, the enzyme digestibility of steamed rice grains can be predicted by mean air temperature after heading.