The formation mechanism of flavor and metabolites during the fermentation of sufu based on carbohydrate metabolism

Understanding the formation mechanism of flavor compounds is essential for controlling the flavor quality of sufu. This study employed metabolomics and metagenomics to investigate the formation mechanisms of key flavor substances in sufu based on carbohydrate metabolism. At KEGG level 3, the annotated gene types and numbers were abundant in glycolysis/gluconeogenesis, starch and sucrose metabolism, amino sugar and nucleotide sugar metabolism, pyruvate metabolism. Additionally, dynamic changes in associated bacteria, enzymes and differential metabolites of metabolic pathways in sufu were investigated. The dominant bacteria associated with the four carbohydrate metabolism pathways include Lactococcus, Weissella, Leuconostoc, Kurthia. The principal associated enzymes were the hydrolases, oxidoreductases, isomerases, transferases, and ligases. Through the reconstruction of metabolic pathways, characteristic flavor substances such as lactic acid, fumaric acid, malic acid, and succinic acid were generated via three reaction chains. This study offers valuable insights for optimizing the fermentation process and improving the flavor quality of sufu.