2019 年 25 巻 2 号 p. 227-235
In this study, we investigated the starch, pasting, thermo-physical, and iodine absorption spectrum properties of Chou 2418, a new amylopectin long-chain (ALC) rice cultivar developed by crossing a high amylose rice cultivar Koshinomenjiman and amylose extender mutant rice cultivar EM10. Chou 2418 exhibited high apparent amylose content, high pasting temperature, and low breakdown viscosity. The iodine absorption spectrum indicates that Chou 2418 contains long-chain glucans of amylopectin and also has high amylose content. Boiled rice grains of Chou 2418 contained more resistant starch (RS) than those of high amylose rice cultivars. The RS content of Chou 2418 rice grains increased following the retrogradation of starch granules, and the grains became hard and non-sticky. The RS content of Chou 2418 was 25 times higher than that of Koshihikari, the most popular rice cultivar. Taken together, these data suggest that Chou 2418 is a suitable raw material for bio-functional foods that help prevent diabetes.
