LAUSR

BACKGROUND Rice eating quality largely dictates consumer preference and the demand of new rice varieties with excellent eating quality from farmers is increasing. Identification of the factors contributing to eating quality is helpful for developing high-quality rice varieties. RESULTS Two groups of rice with different apparent amylose contents (AACs) were used in this study. One group contained four varieties with low AACs (8.8-9.4%), whereas the other contained four traditional varieties with medium AACs (17.2-17.5%). The physicochemical properties, starch fine structure and crystallinity, and storage protein composition of the two groups were analyzed. We found that, in both groups, the rice varieties with high eating quality had more short-chain amylopectin, lower glutelin and prolamin contents, and a higher albumin content. In addition, the low-AAC varieties produced opaque endosperms, which may result from the increased pores in the center of starch granules. CONCLUSIONS Both the fine structure of starch and the storage protein composition were closely related to rice eating quality. In both groups, short branch-chain amylopectin, short-chain amylopectin [degree of polymerization (DP) 6-12], and albumin had positive effects on eating quality. By contrast, long branch-chain amylopectin, long-chain amylopectin (DP 35-60), glutelin and prolamin had adverse effects on eating quality of rice. This article is protected by copyright. All rights reserved.