Characterization and correlation of bacterial community and volatile flavor compounds in xiguajiang, a Chinese traditional fermented condiment

• Xiguajiang (XGJ) is fermented by soybean, watermelon juice and salt as raw materials. • The bacterial community and flavor compounds of different XGJ samples were studied. • Bacillus , Staphylococcus and Weissella were the predominant bacterial genus in XGJ. • Larger relative contents of esters and alcohols were detected in XGJ samples. • The correlations between bacteria and flavor compounds in XGJ were conducted. Xiguajiang (XGJ) is one kind of Chinese traditionally fermented soybean food. The aim of this study was to identify core bacterial communities and volatile compounds and explore their relationships in XGJ samples obtained from different manufacturers. Results showed that Bacillus , Staphylococcus , Weissella , and Chromohalobacter were the predominant bacterial genus, although their relative abundance is quite diverse. Larger relative contents of esters and alcohols were detected in XGJ. Moreover, the results of E-nose analysis indicated that nitrogen oxides compounds, pyrazines, and ketones compounds also played a critical role in XGJ unique flavor. The correlation analysis suggested that 3-methyl-butanol, ethoxybenzene, ethyl acetate, acetaldehyde, and 2-(4-methyl-3-cyclohexen-1-yl)-2-propanyl acetate had a significant correlation with Enterobacter , Clostridium , Pseudomonas , Streptomyces , Weissella , Staphylococcus , and Bacillus . These results may provide vital information to understand the role of the microbiota in developing flavor in XGJ products, and improve the quality and safety of XGJ production in industries.