Physico-ecological Studies on Quality Formation of Rice Kernel IV. Effect of storage on eating quality of rice

Abstract

We examined the effects of short and long-term storage on the eating quality of rice. The texture of cooked rice became harder and less sticky after being stored at higher temperatures and moisture contents for 90 days. The texture of rice stored under excessively dry conditions deteriorated only during the early stages of storage, and became better than rice stored under normal moisture conditions with prolonged storage. The eating quality of rice stored for 6 years was also analyzed. Most of the change in texture occurred during the first 1 to 2 years, and very little change was observed thereafter. Water-insoluble protein and amylose contents showed no significant changes. Fat-by- hydrolysis content, however, increased; this may be a contributing factor in the deterioration of cooked rice texture during storage. A reduction was also observed in the amount of glutamic acid in milled rice as well as a decrease in the ratio of glutamic acid both in milled rice and in the exterior of cooked rice. The pH in the cooking liquid also decreased. These seemed related to the deterioration of the taste of rice. © 1993, CROP SCIENCE SOCIETY OF JAPAN. All rights reserved.