Effects of Different Moisture Contents on Bacterial Flora and Flavor Characteristics of Lightly Salted Large Yellow Croaker during Storage

To investigate the effects of different moisture contents on the storability of lightly salted large yellow croaker at 4 ℃, changes in total volatile basic nitrogen (TVB-N) content, microbial community composition, taste and volatile organic compounds were analyzed during the storage period, and the correlation between microbial community composition and VOCs was examined. The results showed that the shelf-life of lightly salted large yellow croaker with moisture contents of 60%, 55%, and 50% was 27, 33, and 39 days, respectively. During storage, there were significant changes in the bacterial flora, with four specific spoilage organisms (SSOs) being dominant at the end of the shelf-life. In the samples with 60% moisture content, Hafnia alvei (61.22%) and Brochothrix thermosphacta (19.39%) were dominant. In the samples with 55% moisture content, H. alvei (31.13%), B. thermosphacta (29.25%), Carnobacterium divergens (17.92%) and Citrobacter freundii (16.98%) were dominant. C. freundii was not observed at the end of the shelf-life of lightly salted large yellow croaker with 50% moisture content, and H. alvei (43.96%) and B. thermosphacta (37.36%) were dominant, respectively. The electronic tongue results showed that the trend of response values was basically the same among the three groups of samples. A total of 29 VOCs were detected by gas chromatography-ion mobility spectrometry (GC-IMS), including seven alcohols, six esters, four ketones, four aldehydes, three amines, two heterocycles, one olefin, one ether and one terpene. The fingerprinting results showed no significant difference in the composition of VOCs among the groups. Pearson’s correlation analysis showed that H. alvei and B. thermosphacta were positively correlated with amines for all groups.