Abstract: Whey is a by-product of cheese making, which is rich in nutrition. Selecting lactic acid bacteria and yeast to prepare whey fermented wine can obviously improve the added value of whey production. In this study gas chromatography-mass spectrometry (GC-MS) was used to analyze the changes of important aroma components in whey wine, and high-throughput sequencing technology was used to analyze bacterial community changes in whey wine, and correlation analysis was conducted. The results showed that the total quantity of flavor substances increased during the fermentation process of whey wine. A total of 102 volatile flavor substances were detected, among which ester was the highest. Through the calculation of aroma activity value, it can be concluded that more than 15 kinds of aroma substances, such as ethyl benzoate, ethyl acetate and ethyl butyrate, constitute the important aroma components of whey fermented wine. Lactobacillus is the absolute dominant bacterium in the early stage of fermentation, while Lactobacillus and Lactococcus become the absolute dominant bacterium with the progress of fermentation. Bacterial function prediction showed that the metabolic activities of whey were mainly amino acid metabolism and carbohydrate metabolism. Further correlation analysis showed that most flavor substances were positively correlated with Lactococcus and Raoultella. The genera Lactococcus and Raoultella showed significant positive correlation with ethyl phenyl acetate, ethyl decanoate, ethyl caproate and ethyl acetate. Lactobacillus is positively correlated with citral, caprylic acid, decanoic acid, 4-ethylphenol, ethyl heptanoate, methyl decanoate and ethyl oleate. This study was intended to provide theoretical basis for the selection of starter and flavor control of whey wine.

Key words: whey wine, high-throughput sequencing, bacterial diversity, functional prediction, the aroma components