高产乙酸乙酯酵母菌的筛选及其在清香型小曲白酒生产中的应用

该研究利用WL营养琼脂培养基从浓香型大曲中分离纯化酵母菌，采用形态学观察和分子生物学技术对其进行鉴定，经过高粱汁培养基发酵初筛、高粱固态培养基发酵复筛，获得高产乙酸乙酯的酵母菌，并将其应用于清香型小曲白酒工业生产。结果表明，从浓香型大曲中分离得到2株酵母菌，编号为Y87和Y88，经鉴定分别为异常威克汉姆酵母（Wickerhamomyces anomalus）、酿酒酵母（Saccharomyces cerevisiae），其中菌株Y87乙酸乙酯产量最高，高粱汁液态发酵和高粱固态发酵乙酸乙酯产量分别达到1.13 g/L、1.14 g/L，菌株Y87强化曲酿造的白酒乙酸乙酯含量提高36.6%，杂醇含量降低7.1%，正丙醇含量降低16.1%，感官评分为90.7分，该白酒具有清香型小曲白酒的典型特征，入口醇甜，清香纯正，说明菌株Y87可显著提高小曲白酒的品质。

Screening of high-yield ethyl acetate yeast and its application in the light-flavor Xiaoqu Baijiu production

Yeasts were isolated and purified from strong-flavor Daqu by WL nutrient agar medium, and identified by morphological observation and molecular biology technology. After the preliminary screening of sorghum juice medium fermentation and the secondary screening of sorghum solid-state medium fermentation, the high-yield ethyl acetate yeasts were obtained and applied in the industrial production of light-flavor Xiaoqu Baijiu (Chinese liquor). The results showed that 2 strains of yeast were isolated from strong-flavor Daqu, numbered as Y87 and Y88, and were identified as Wickerhamomyces anomalus and Saccharomyces cerevisiae, respectively. Among them, the yield of ethyl acetate of strain Y87 was the highest, which was 1.13 g/L and 1.14 g/L in the liquid and solid fermentation, respectively. In addition, the ethyl acetate content in Baijiu brewed with strain Y87 fortified Jiuqu increased by 36.6%, the fusel oil content decreased by 7.1%, the n-propanol content decreased by 16.1%, and the sensory evaluation score was 90.7. The Baijiu had typical characteristics of light-flavor Xiaoqu Baijiu, with mellow and sweet entrance and pure fragrance, indicating the strain Y87 could significantly improve the quality of Xiaoqu Baijiu.