Effects of enzymes on ester production during the course of a Chinese liquor fermentation as discussed by correlation analysis and path analysis

Abstract

During the course of a Chinese liquor fermentation, the enzyme activities in the fermenting grains have important effects on ester production. Activities of six kinds of major hydrolases (including amylase, glucoamylase, protease, cellulase, pectinase and lipase) and the production of esters (including total esters, ethyl acetate, ethyl butyrate, ethyl caproate and ethyl lactate) were measured in the fermenting grains. The correlation coefficient between enzyme activities and ester production was calculated through correlation analysis, and the direct and indirect path coefficients of enzyme activities on ester production were obtained by path analysis. The results showed that enzymes had not only direct effects, but also indirect effects via other enzymes on ester production, indicating that the origin and composition of the enzyme effects on ester production were specific.