Analysis of Metabolite Composition and Isolation of Dominant Bacteria in Two Hubei Special Wheat Sauce

To explore the metabolite composition and bacterial phase composition of Hubei traditional wheat sauce, the physicochemical indexes determination, non-targeted metabolomics analysis and dominant strains isolation were conducted in this study. The results showed that both wheat sauces met the requirements of GB 2718-2014 National Food Safety Standard for Brewing Sauce. A total of 236 non-volatile metabolites were identified by liquid chromatograph-tandem mass spectrometry (LC-MS/MS), mainly organic acids and their derivatives, fatty acyls, benzene and substituted derivatives, among which 195 non-volatile differential metabolites were screened. Moreover, 178 volatile metabolites were identified by gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS), mainly organic acids and their derivatives, organic oxygen compounds, lipids and lipid-like molecules, among which 106 volatile differential metabolites were screened. The results of bacterial species identification indicated that the dominant species were Bacillus, Aspergillus oryzae and Starmerella etchellsii. Collectively, this study laid a solid theoretical foundation for the analysis of flavor composition and identification of dominant bacteria in traditional wheat sauce.