Microbial succession, identification, and spoilage potential of dominant bacteria in ready-to-eat salmon under different storage conditions.

Abstract

As a popular high-value seafood with rich nutritional benefits, ready-to-eat salmon is highly susceptible to microbial spoilage, posing risks to its quality and food safety. This study investigated bacterial community dynamics in commercial ready-to-eat salmon under different temperatures (4 °C/25 °C) combined with packaging conditions (aerobic/vacuum) using high-throughput 16S rRNA gene sequencing, and further explored the species-specific spoilage characteristics of five specific spoilage organisms (SSOs) via culture-dependent methods. The results revealed that bacteria under vacuum storage at 4 °C were dominated by Photobacterium as the sole genus-level biomarker (LDA > 5.0), while aerobic storage favored the dominance of Pseudomonas. At 25 °C, Lactococcus and unclassified Enterobacteriaceae both became dominant taxa in vacuum-packaged groups, while in aerobic groups, the bacterial community exhibited a multi-genus co-dominance pattern throughout storage. Five SSOs isolated from spoiled salmon samples were selected for spoilage capacity evaluation in disinfected salmon samples, including Carnobacterium divergens, Brochothrix thermosphacta, Hafnia alvei, Pseudomonas fluorescens, and P. fragi. P. fragi exhibited the highest lipid oxidation (TBARS) in salmon samples, and H. alvei accumulated the most total volatile basic nitrogen (TVB-N), while each SSO produced unique volatile profiles. These findings contribute to a better understanding of bacterial succession and species-specific spoilage potential in ready-to-eat salmon, supporting future studies on seafood spoilage control.