Effects of Exogenous Inoculums on Microbial Community and Volatile Flavor Compounds of Fermented Hot Pepper

In this study, fermented hot pepper products were prepared using Kluyveromyces lactis Km and Lactobacillus plantarum QB3 singly and in combination. The physicochemical analysis showed that fermented hot peppers inoculated with QB3 consumed the most reducing sugar, resulting in the fastest drop of pH of the fermentation broth, and an increase in the contents of short-chain fatty acids and vitamin A by 62.5% and 13.8%, respectively. QB3 grew dominantly in fermented hot peppers, reducing the α-diversity of microorganisms. A total of 73 volatile compounds were detected in fermented hot peppers, 46 of which may contribute to the flavor. Correlation analysis showed that 148 species of microorganisms may be involved in the synthesis of 71 compounds, and L. plantarum and K. lactis may be involved in the synthesis of 26 volatile compounds. K. lactis was key to the formation of flavor compounds, and the synthesis of most volatile compounds was negatively correlated with L. plantarum. This study may provide a theoretical basis and technical support for the preparation of fermented hot pepper products with various flavors by inoculating lactic acid bacteria and yeast, and provide a reference for the flavor diversification of fermented food.