Unraveling characterizations of bacterial community and spoilage profiles shift in chilled pork during refrigerated storage

Changes in bacterial community composition and bacterial counts of chilled pork during storage at 4 °C were unraveled by culture-dependent method and culture-independent method. Physical and chemical analyses including drip loss, total volatile basic nitrogen (TVB-N), pH, and surface color were also performed to estimate its quality and shelf life. A total of 37 phyla, 575 genera and 843 species were identified in all samples by high-throughput sequencing technology during 10 days’ storage. At the phylum level, Proteobacteria and Firmicutes were the dominant phylum. At the genus level, Pseudomonas spp., Acinetobacter spp., Pantoea spp., Brochothrix spp. and Raoultella spp. were the dominant genera with their average relative abundance above 5%. In addition, 12 species with average relative abundance more than 1% were found. These dominant bacteria were main pathogenic or spoilage bacteria, and seriously affected the quality of chilled meat. Based on the results of total viable counts (TVC), TVB-N level and sensory evaluation, the shelf life of chilled pork stored at 4 °C was no more than 3 days. Through the analyses of the TVC and the microbial community structure during the spoilage of chilled pork, the main microorganisms causing spoilage were revealed, which will guide significance for further control microbial quality of chilled pork.