Comprehensive analysis of spoilage characteristics of refrigerated hairtail by microbiome and metabolomics.

Hairtail is prone to spoilage during refrigerated storage and it is due to microbial activity, which will directly lead to changes in the composition of metabolites in vivo. This study systematically elucidates the spoilage phenomena in hairtail during eight days of refrigeration at 4 °C through multi-omics analysis. Pseudomonas and Shewanella were identified as key spoilage bacteria, and their nutrient utilization pathways were different Pseudomonas dominated the early stage and used monosaccharides; however, Shewanella appeared in the later stage, and its metabolism is heavily dependent on amino acids and nitrogen-containing compounds such as TMAO released in large quantities in the later stage of spoilage. Non-targeted metabolomics results revealed a total of 62 differentially expressed metabolites. Metabolic pathway enrichment analysis revealed that cysteine and methionine metabolism, tyrosine metabolism and nucleotide metabolism played pivotal roles in the putrefaction process. Moreover, the study identified 7 metabolites (such as Lys-Met, Nicotinic Acid Adenine Dinucleotide) that showed a significant correlation with the dominant spoilage bacterium Pseudomonas through correlation analysis; while two other metabolites (such as Inosine 5'-Monophosphate, Tyramine) were significantly correlated with the primary spoilage bacterium Shewanella. The integration of microbiome and metabolomics analyses has enabled the precise identification of key spoilage microorganisms and metabolites in chilled hairtail, providing crucial evidence for developing targeted preservation techniques.