Abstract:
To reveal the change pattern of microbial community structure in fresh pork during storage, samples were stored at 4 ℃ in this experiment. Five samples were collected at 0, 1, 3, 5, and 7 days respectively. The changes in the total number of colonies, the total number of mold and yeast, and the content of volatile basic nitrogen were measured. Furthermore, the bacterial 16S rRNA genes and fungal ITS high-throughput sequencing were further used to analyze the changes in the structure of microbial flora. The results showed that throughout the storage period, both the TVC and TVB-N content exhibited upward trends, increasing from 3.88 lg CFU/g and 5.77 mg/100 g to 6.83 lg CFU/g and 23.26 mg/100 g, respectively (
P<0.05). The mold and yeast counts showed a trend of first increasing and then decreasing, with a significant increase to 2.71 lg CFU/g observed at 3 days of storage (
P<0.05). Both Chao1 richness and Shannon diversity indices of bacteria and fungi exhibited significant declines (
P<0.05). The
β-diversity analysis revealed that the structures of bacteria and fungi were significantly difference across storage periods (
P<0.05). At the genus level, the relative abundance of
Brochothrix increased significantly during the storage stage and reached to 70.56%, becoming the dominant genus at Day 7, while
Lactococcus and
Acinetobacter showed marked depletion (
P<0.05). Fungal communities were predominated by
Kurtzmaniella,
Debaryomyces,
Aspergillus,
Filobasidium, and
Candida. Notably, the relative abundance of
Kurtzmaniella increased significantly with prolonged storage (
P<0.05), contrasting with reductions in
Candida,
Filobasidium, and
Aspergillus (
P<0.05). Spearman correlation analysis demonstrated significant positive correlations between the bacterial genera
Brochothrix and
Lactococcus and the fungal genera
Kurtzmaniella and
Candida, respectively. This study highlights
Brochothrix,
Lactococcus,
Acinetobacter, and the fungal taxa
Kurtzmaniella and
Candida as critical contributors to chilled pork spoilage. These findings provide a theoretical foundation for optimizing shelf-life extension and quality control strategies in chilled pork preservation.