Open crack formation in rice with cracked endosperm and cracked surface during soaking

Abstract

Open crack formation (suishin-ressho) in polished rice during soaking tends to result in damaged cooked rice (suihan-hokai-ryu) ; and is one of the important index which affect the taste of cooked rice. In this study, the open crack ratio in polished rice (Oryza sativa L. cv. Akitakomachi) during soaking was determined at various moisture content and water temperature. Polished rice without crack (seiryu) before soaking and polished rice with cracked endosperm (doware-mai), and cracked surface (hibiware-mai) were used in this measurement. Results showed that open crack ratio increased with decrease of both moisture content of polished rice and water temperature. Open crack ratio was the highest in rice with cracked surface, and followed by rice with cracked endosperm and rice without cracks. In addition, the variation of open crack ratio with time during soaking was well expressed by using Weibull's distribution function.