Strong-flavor Baijiu is a typical representative of traditional fermented Baijiu in China. Its cellar flavor is rich and its flavor is harmonious, which is loved by consumers. Its product market share is high. At present, due to the unclear internal relationship between the important microorganisms that affect the quality of Baijiu and the formation of key flavor substances in the traditional brewing process, extensive experience mode is still used in many aspects of the production of strong-flavor Baijiu, with low efficiency and poor batch stability, difficult to achieve quality improvement, and slow progress in standardization industrialization. The research confirmed that the esters produced by the esterification of acid and alcohol catalyzed by microbial ester synthase during the brewing process are the key to determine the style and quality of strong-flavor Baijiu. Targeted bioaugmentation may be one of the effective ways to regulate the succession of microbial communities and the production of flavor metabolic products in Baijiu fermentation. However, due to the high acid fermentation environment formed by the microbial metabolism of lactic acid, acetic acid and other acid substances during the brewing process of strong-flavor Baijiu, most of the exogenous ester producing functional microorganisms are difficult to adapt to the environment, thus inhibiting the synthesis of important flavor substances such as ethyl caproate. Therefore, it is particularly important to screen functional microorganisms with high yield of ethyl hexanoate and high acid resistance, and then explore their impact on the succession of microbial communities and the generation of flavor substances in the process of Baijiu brewing.

In this study, a Saccharomyces cerevisiae YS219 strain with high yield of ethyl hexanoate and high acid resistance was excavated. On the basis of constructing a simulated fermentation system for Baijiu, the strain was used to bioaugmentation in the fermentation process of strong-flavor Baijiu, explore the rule of microbial community succession and flavor compounds change in the fermentation process of strong-flavor Baijiu, and deeply analyze the correlation between important microorganisms and the formation of flavor compounds. The study found that the microbial community structure of strong-flavor Baijiu fermentation process changed significantly after adding the functional strain Saccharomyces cerevisiae, and the content of important flavor compounds ethanol (35.967 mg/kg) and ethyl hexanoate (214.367mg/kg) increased significantly.

source: https://mp.weixin.qq.com/s__biz=MzIyODA3NTc0NA==&mid=2650058074&idx=3&sn=e58bb30b316e885f5d14c5e524c84ac4&chksm=f10f34dc490e04b75601e67d8f60f4bcfc4af10d17bab0c4e9de60bbd3fb0e9541ff9f384107&scene=27