Reduction of Amino Acid Content in the Sake by Rice Germ Addition to Moromi Mash

Study on the Brewing of Sake with Excellent Taste and Flavor (Part I)

Abstract

To examine the effect of rice germ addition to moromi mash on the quality of the obtained sake, several pilot scale brewings (total amount of 200 g of rice) were carried out. The sake brewed with 10 g of rice germ has lower amino acid and organic acid contents. Among amino acids, valine, leucine, and isoleucine, from which higher alcohols were formed in yeast cells, reduced and the related higher alcohols increased. These results suggest that rice germ accelerates amino acid uptake by yeasts in moromi mash. Acetic acid and pyruvic acid reduced in the sake, whereas other main organic acids, lactic acid, malic acid and succinic acid did not.