In sake brewing, the steamed rice is used in 2 ways, added to sake-mash and making rice-koji. Rice-koji is made from the steamed rice by using koji starter, 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, Gohyakumangoku and 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 koji starter and sake rice cultivars on the sake metabolites, we performed small-scale sake-making tests using the above 3 rice cultivars and 3 koji starters. Finally, we demonstrated that some of the characteristic components/metabolites of sake from KOS are affected by the koji starter. Thus, in addition to rice cultivar, koji starter plays an important role for establishment/maintenance of the quality of the final product.

在清酒酿造中，米饭有两种使用方式，加入清酒泥中，制成米曲。大米曲使用米曲发酵剂从蒸米制成，其质量是清酒香气/味道的重要决定因素。起见稻Koshitanrei（KOS）中的溶液通过杂交2个起见水稻品种，新泻县开发Gohyakumangoku和山田锦。最近，我们通过使用UPLC-QTOF-MS进行代谢组分析，报道了由KOS制成的清酒中的特征性成分/代谢物。在这项研究中，研究曲的效果发酵剂和清酒品种中的清酒代谢物，我们使用上述3种水稻品种和3种曲发酵剂进行了小型清酒试验。最后，我们证明了来自KOS的清酒的某些特征成分/代谢物受制于曲液发酵剂的影响。因此，除了水稻品种外，曲曲发酵剂对于最终产品质量的建立/保持也起着重要的作用。