Abstract: In this work, the changes of the microbial community structure, taste and water distribution during the fermentation of Suanzuo fish were investigated. The microbial community was detected by Illumina MiSeq sequencing. Lactobacillus, Weissella and Staphylococcus were found to play the dominant role in the fermentation process. The abundance of Staphylococcus attained the maximum value of 64.65% on day 24, followed in decreasing order by Tetragenococcus, Lactobacillus, Macrococcus and Weissella. After completion of the fermentation on day 24, the concentration of total free amino acids increased to 1 406.09 mg/100 g from 380.61 mg/100 g. The taste-active amino acids Asp, Glu, Ala, Val, Met, Phe, Lys and His were detected in Suanzuo fish. In the product, the taste activity value (TAV) of Glu was 30.69, which made Glu the most prominent contributor to the overall taste of Suanzuo fish. It was observed that the percentages of immobile and free water decreased obviously while the percentage of bound water increased gradually during the fermentation process. This change was consistent with the change of fish flesh texture. This study provides theoretical support for the industrial development of traditional ethnic aquatic foods in China.

Key words: Suanzuo fish; fermentation; microbial community; amino acid; water