The microbial communities and flavour compounds of Jiangxi yancai, Sichuan paocai and Dongbei suancai: Three major types of traditional Chinese fermented vegetables

The microbial communities, their predicted functional roles and associated flavour compounds in three typical traditional Chinese fermented vegetable (TCFV) foods, viz. Jiangxi yancai (JX), Sichuan paocai (SC) and Dongbei suancai (DB) were revealed by gene sequencing, predictive functionality and correlation analysis. Bacterial community analysis showed that Lactobacilli made up a large proportion (up to 77.6%) of the species in each food type and revealed clear differences in bacterial community structure among the three types. Lactobacillus sakei, Lactobacillus acetotolerans, and Pediococcus pentosaceus were found to be markers of the DB, SC, JX types, respectively. Overall, 8 organic acids (OAs), 17 amino acids (AAs) and 97 volatile flavour compounds (VFCs) were detected. Several Lactobacilli were closely correlated with more than 20 flavour compounds. Based on their abundance and putative contributions to flavour, Lactobacillus acetotolerans and Lactobacillus sakei may be considered core functional microbiota of each of the three TCFV foods. Functional analysis showed that microbial metabolism of carbohydrates, amino acids and nucleotides is a major determinant of the characteristics of all three TCFV product types. The systematic method used in this study allows identification of the key microorganisms involved in vegetable fermentation and provides a deeper understanding of their contribution to TCFV products.