Abstract:Amino acids play an important role in forming the flavor of dongbei suancai (sauerkraut from Northeast China). Therefore, metabolomics was used to study the amino acid transformation pathway of artificially inoculated sauerkraut from Northeast China during fermentation. The results reveal that 638 metabolites were detected during the fermentation of the sauerkraut. Amino acids, peptides, and their analogs (25.43%) were the main metabolites, and they increased significantly in the middle stage of fermentation. The metabolic pathways of artificially inoculated fermented sauerkraut mainly involved amino acid, lipid, other secondary metabolite biosynthesis, carbohydrate, nucleotide, and other metabolic pathways. Meanwhile, peptides (33.33%) were the main compounds involved in metabolic pathways. During fermentation, 12 amino acids with important contributions to the sour and umami taste of the sauerkraut were identified. Simultaneously, most of the flavor of sauerkraut inoculated and fermented at 20 ℃ formed in the first 10 days. In addition, the pathways with significant enrichment of amino acid metabolites mainly involved arginine and proline metabolism, cysteine and methionine metabolism, glutathione metabolism, serine metabolism, histidine metabolism and lysine degradation. The results show that the metabolic pathways of amino acid substances were varied during fermentation of inoculated sauerkraut; this may hold great significance for the adjustment of the flavor of sauerkraut from Northeast China.
