Detailed analysis of amylose content of rice grains and its relation to the physical properties of cooked rice

Amylose content is a critical factor in the physical characteristics of cooked rice. This study analyzed the relationship between amylose content in grain and the physical characteristics of cooked rice by analyzing amylose content in stratified layers of rice grains. Amylose content in grain differed among cultivars and showed annual change in every analyzed cultivar. Regarding amylose content and cooked rice, "surface hardness" was related to amylose content localized on the surface part of grain and in the central part; "overall hardness" was related to overall amylose content, including the central part; "surface stickiness" was partly related to amylose content localized on the surface part; "surface balance degree" was partly associated with amylose content of the surface part; and "overall balance degree" was correlated with amylose content of the overall part. These results provide a basis for understanding the contribution of amylose to the properties of cooked rice.