抄録
The laboratory-scale sake mashing was carried out using rice of various polishing ratio; 70%, 80% and 90%.Amino acidity of sake mash was the lowest at polishing ratio 90%, in spite of highprotein content of polished rice.To elucidate its mechanism, the balance of nitrogen in sake mashwas investigated, and results described below were obtained. More than 50% of nitrogen releasedfrom koji and steamed rice was taken in yeast cells in sake mash.The amount of nitrogen releasedfrom both koji and steamed rice was the largest at polishing ratio 90%, whereas, the amount of nitrogen taken in yeast cells was about 1.5 times as large at polishing ratio 90% as that at polishing ratio 70%. Consequently the nitrogen concentration of liquid phase was lowest in sake mash atpolishing ratio 90%. The cell concentration of yeast in sake mash at polishing ratio 90% was 2.5times as high as that at polishing ratio 70%, whereas the amount of nitrogen per dry weight of yeast was about the same regardless of polishing ratio, though the dry weight per 108 yeast cells at polishing ratio 70% was 1.7 times as high as that at polishing ratio 90%. From these results, it was comprehensible that the amount of nitrogen taken in yeast cells in sake mash was the largest at polishing ratio 90%.
