YUAN Yinghao, LEI Yuli, LIU Yuchen, ZHOU Li, LIU Aiping, LI Jianlong, HU Kaidi, LI Qin, ZHAO Ning, GUO Mingye, LIU Shuliang
This study conducted an intensive fermentation with aroma-producing yeast-Wickerhamomyces, during the fermentation process, monitored the key physicochemical factors such as temperature, moisture, and total acid of the grains, analyzed the structure of the vinegar flora by Illumina Miseq high-throughput sequencing, analyzed the volatile components of the vinegar by headspace solid phase microextraction gas chromatography-mass spectrometry, and combined with the sensory evaluation, to determine the effect of the enhanced fermentation.The effect of fermentation was determined.Results showed that the key physicochemical indexes of the control group and the aroma-producing yeast group differed to a certain extent during the fermentation process without adding aroma-producing yeast as the control, among which the total acid content of the vinegar spirits in the aroma-producing yeast group increased by 4.7%, and the utilization rate of starch increased by 4.80%, the aroma-producing yeast group increased aroma significantly, and the relative content of alcohols in the vinegar increased by 187.34%, the relative content of volatile acids increased by 45.75%, and the relative content of esters increased by 128.99%, especially phenylethanol, 2,3-butanediol, acetic acid, ethyl acetate, ethyl lactate, and other contents increased significantly.Lactobacillus, Acetobacter, Bacillus, Pichia, Aspergillus, Saccharomyces, Issatchenkia, and Wickerhamomyces were the main dominant genera in the fermentation process.Compared with the control group, the introduction of aroma-producing yeast increased the relative abundance of Wickerhamomyces in the pre-fermentation and mid-fermentation periods, and disturbed the Lactobacillus, Acetobacter, Picrytus, Saccharomyces, and Trichoderma in the grains of vinegar, which resulted in differential changes in the bacterial flora structure.The results of this study indicate that the aroma-producing yeast can significantly improve the flavor quality of bran vinegar, and provide a reference for the improvement of flavor quality of bran vinegar.