Changes in microbial composition and quality characteristics of yellowfin tuna under different storage temperature

Yellowfin tuna is one of the commercially important fish varieties, and inappropriate storing may deteriorate its safety and quality. This study aimed to investigate the microbial composition and quality characteristics of yellowfin tuna stored at different temperatures for varying amounts of time. With an increase in the storage temperature and storage time, the biogenic amines, the total volatile basic nitrogen TVB-N, and the total viable cell count steadily increased, which influenced the quality of tuna. The most significant histamine concerning food safety reached levels of 21.25, 235.05, 1166.18, and 3799.29 mg/kg, respectively. The values of total viable cell counts were increased to 7.04, 7.97, 8.24, and 8.91 log CFU/g after storage at 0, 4, 10, and 20 °C for 12 days, 7 days, 7 days, 3 days, respectively. Additionally, changes in microbial composition were evaluated by high-throughput sequencing, and the results showed that Pseudomonas was the dominant spoilage bacteria in yellowfin tuna. The bacterial dynamics and their correlation with biogenic amines and TVB-N in yellowfin tuna were analyzed. A positive correlation between Pseudomonas, Shewanella, Morganella, Acinetobacter, and biogenic amines was found. Pseudomonas showed significant correlation with histamine, cadaverine, and putrescine. This study provides insights into yellowfin tuna quality and microbial composition, which provide theoretical guidance for maintaining seafood safety and quality during distribution and storage.