The formation mechanisms of key flavor substances in stinky tofu brine based on metabolism of aromatic amino acids

[Display omitted] •Changes in phenolsand indoles substances in brine were determined by HS-SPME-GC-MS.•Key flavor substances in brine were phenol, p-cresol, indole, and 3-methylindole.•A network diagram of the formation of phenols and indoles substances was constructed.•Metabolic reaction of precursor AAA (aromatic amino acid) generate flavor substance.•Key bacteria and enzyme genes for producing flavor substances were revealed. Understanding the formation mechanism of the flavor compounds in stinky tofu brine is crucial for controlling the flavor quality of Changsha stinky tofu. Dynamic changes in associated bacteria, enzymes, and differential metabolites in the metabolic pathway of aromatic amino acids in brine were investigated. Results showed that phenol (0.39～89.96 μg/mL), p-cresol (0.19～389.62 μg/mL), indole (1.14～242.97 μg/mL), 3-methylindole (0.14～3.00 μg/mL) were the key flavor substances of brine. The main associated bacteria Clostridiales bacterium SYSU GA17129, Aneurinibacillus aneurinilyticus, and Anaerosalibacter massiliensis were significantly positively correlated with key flavor substances (P