Improvement in quality of sake brewed from low-glutelin rice for sake brewing [Japanese]

摘要

To resolve the problems raised in previous tests of sake brewing using low-glutelin rice, we examined accelerated dissolution of the rice grains either through addition of a commercial enzyme or through increase in the ratio of koji in the moromi mash in a small-scale test. Following enzyme addition, SEM observation and SDS-PAGE analysis showed marked collapse of rice grains in moromi mash protein body type II (PB-II) was also almost entirely dissolved. In samples treated with enzyme addition and samples in which the ratio of koji was 30%, the resultant sake did not have the characteristic odor of low-glutelin rice mashing. Subsequently, an effect equal to that achieved in the small-scale sake-brewing test was confirmed in a plant-scale sake-brewing test through addition of a commercial enzyme for moromi mash. Analysis of the starch value and crude protein content in the moromi mash showed that the amount of starch and protein eluted from raw material rice was greatest in samples subjected to enzyme addition. It became clear that the protein composition of the raw material rice greatly affects the chemical form of the nitrogen compound regardless of whether enzyme has been added to the moromi mash.