Characterizing flavor development in low-salt Chinese horse bean-chili paste through integrated metabolomics and metagenomics

This study utilized metabolomics and metagenomics to investigate the microbial composition and functions in low- and high-salt Chinese horse bean-chili pastes (CHCPs). The results showed that 25 key metabolites were identified to distinguish the flavor attributes between the two samples. Leuconostoc was identified as the dominant microbiota in low-salt CHCP, while Pantoea prevailed in the high-salt CHCP. Compared to traditional high-salt fermentation, low-salt and inoculated fermentation promoted the increase in the relative abundances of Companionlactobacillus, Levilactobacillus, Tetragenococcus, Zygosaccharomyces and Wickerhamiella as well as the enrichment of carbohydrate and amino acid metabolic pathways, which contributed to the enhancement of characteristic flavor compounds. Further metabolic pathway reconstruction elucidated 21 potential microbial genera associated with the formation of key metabolites, such as Leuconostoc, Levilactobacillus, Pantoea, and Pectobacterium. This study may provide insights for optimizing the fermentation process and improving the flavor quality of low-salt CHCP and similar fermentation products. KEYWORDS: Low-salt fermentation Hight-salt fermentation Chinese horse-bean chili paste Flavor formation Metabolomics Metagenomics.