Effect of kojistarter on metabolites in Japanese alcoholic beverage sake made from the sake rice Koshitanrei

ABSTRACTIn sake brewing, the steamed rice is used in 2 ways, added to sake-mash and making rice-koji. Rice-kojiis made from the steamed rice by using kojistarter, and its quality is an important determinant of the aroma/taste of sake. The sake rice Koshitanrei(KOS) was developed in Niigata Prefecture by crossing 2 sake rice varieties, Gohyakumangokuand Yamadanishiki. Recently, we reported the characteristic components/metabolites in sake made from KOS by conducting metabolome analysis using UPLC-QTOF-MS. In this study, to investigate the effect of kojistarter and sake rice cultivars on the sake metabolites, we performed small-scale sake-making tests using the above 3 rice cultivars and 3 kojistarters. Finally, we demonstrated that some of the characteristic components/metabolites of sake from KOS are affected by the kojistarter. Thus, in addition to rice cultivar, kojistarter plays an important role for establishment/maintenance of the quality of the final product.