Screening, identification and characterization analysis of aroma-producing yeasts in sauce-flavor Daqu

Abstract

In order to obtain yeast strains with superior ester-producing and aroma-producing abilities, the yeast strains from sauce-flavor (Jiangxiangxing) Daqu were primarily screened and re-screened by measuring esterase activity and total ester content, respectively. The volatile flavor compounds in the sorghum juice fermentation liquid by yeast were analyzed using GC-MS, and the aroma-producing yeast was obtained. The screened aroma-producing yeast was identified through morphological observation, physiological and biochemical experiments, and molecular biology techniques, and its growth characteristics and tolerance were analyzed. The results showed that an aroma-producing yeast FBKL2.0519 was screened out through preliminary screening, re-screening, and GC-MS analysis. Its total ester production reached 3.70 g/L, which could effectively increase the types and contents of volatile flavor substances in the sorghum juice fermentation liquid, and the main flavor substance ethyl acetate content was 19.44 mg/L. The aroma- producing yeast FBKL2.0519 was identified as Wickerhamomyces anomalus. The aroma-producing yeast FBKL2.0519 had good growth characteristics and tolerance, and it could grow in a stressful environment with ethanol volume fraction 10%, pH 3, and temperature 40 ℃. The aroma-producing yeast FBKL2.0519 had good application potential in improving Baijiu flavor.

Keywords

• aroma-producing yeast|screening and identification|volatile flavor compound|characteristic analysis