Evaluation of spoilage indexes and bacterial community dynamics of modified atmosphere packaged super-chilled pork loins

Modified atmosphere packaging (MAP) is widely adopted for meats and meat products. While an effective cold chain may provide microbial safety during storage, several key spoilers, active at these conditions, can still induce spoilage. Thus, the objective of this study was to evaluate the effects of MAP on spoilage indexes and bacterial population of predominant spoilers in fresh pork loins at super-chilling (−2 °C) storage for 28 d. The results showed a negligible color improvement in Group A after 14 d while reduced TVB-N (13.33 vs 16.58 mg N/100 g), TBARS (1.79 vs 2.28 MDA/kg), TVC (6.5 vs 7.2 log CFU/g), and psychrotrophic bacteria count (6.1 vs 6.8 log CFU/g) were found in Group B in comparison to control group (D) at the end of storage. The abundance of Pseudomonas spp., Brochothrix spp., lactic acid bacteria, and Photobacteria spp., regarded as predominant spoilers of meat, in general, was influenced by the gas composition used in the packages. Although the abundance of specific spoilers, such as Serratia liquefaciens and Carnobacterium divergens, were reduced in Group C, significant inhibitions of Pseudomonas spp., Brochothrix spp., Serratia spp., Hafnia spp., Acinetobacter spp., Kurthia spp., and Kocuria spp. Were detected in Group B packs over time. Nevertheless, Pseudomonas spp. And Brochothrix spp. Were the abundant spoilers detected among different groups, hence, it is necessary to elucidate their adaptive mechanisms in the cold chain. Further studies into their spoilage and adaptive mechanisms are needed in order to control their proliferation in meat during storage.