Exploring the impact of cold and modified atmosphere packaging storage on prepared meat products: Temporal dynamics of the bacterial community and quality analysis

The objective of this paper is to study the impacts of modified atmosphere packaging (MAP) with different gas compositions (70 % O₂/20 % CO₂/10 % N₂;80 % CO₂/20 % N₂) on quality and dynamic microbial changes of marinated pork chops during the storage period under super-chilled and cooling conditions. Compared with the shelf life of 14 days at 4 °C, the shelf life of prepared pork chops was extended to 56 days at −2 °C storage. The content of carbonyl groups, thiobarbituric acid reactive substances (TBARS), total volatile basic nitrogen (TVB-N), and total viable count (TVC) values were significantly reduced (P < 0.05). The super-chilled storage effectively delayed the oxidation of proteins and lipids. The 16srRNA gene amplicon sequencing results showed that the microbial communities of marinated pork chops between −2 °C and 4 °C storages showed a high similarity, except for Serratia, a specific spoilage bacteria in high O₂ MAP storing at 4 °C. The gas composition significantly affected the bacterial communities in the different treatment groups (P < 0.05). The spoilage biomarkers in high O₂ and high CO₂ MAPs were Brochothrix and Leuconostoc, respectively. Significant differences were also observed between high O₂ and high CO₂ MAPs for the functional potentials based on KEGG, especially for carbohydrate and amino acid metabolism (P < 0.05). The results of this paper provide valuable information for the preservation strategies of prepared meat products.