Studies on the Fermentation Control of Sake Mash (XI)

Relation between Fermentation Tamperature and the Production of some flavor Compounds

Abstract

Effects of fermentation temperature (at 15, 20, 25°C) on the production of some flavor compounds. during fermentation of the saccharified rice solution (Koji+ steamed rice+ water) by Kyokai No.7 and Awanashi yeasts were studied.
1. Changes of flavor components were shown as the ratio of the concentration of these components to the concentration of ethyl alcohol produced. With increase in the fermentation temperature, this ratio increased in i-butanol, i-amyl alcohol, ethyl lactate and phenethyl alcohol.
On the other hand, this ratio decreased in acetoin, diacetyl and i-amyl alcohol.
n-propyl alcohol, n-butyl alcohol, ethyl lactate, phenethyl alcohol and ethyl caprate were not affected greatly by the fermenting temperature.
2. Ethyl caprate, phenethyl acetate, i-amyl acetate, acetoin and diacetyl increased as alcoholic fermentation proceeded, and then decreased at the later stages of the fermentation. Phenethyl alcohol, ethyl r.henylacetate and ethyl laurate increased during fermentation and then decreased slightly at the end of fermentation.
On the other hand, aliphatic higher alcohols and ethyl lactate were continued to increase during fermentation.
These results were compared with behaviors of the flavor compounds in sake mash during the fermentation.