Effects of Pseudomonas fluorescens and Brochothrix thermosphacta on Quality Changes of Pork during Low-temperature Storage

In order to investigate the correlation between Pseudomonas fluorescens and Brochothrix thermosphacta and pork quality, in this study, the microbial load, pH, color (L*, a* and b* values), texture, total sugar content, total volatile basic nitrogen (TVB-N) value and thiobarbituric acid reactive substances (TBARS) value were determined and the microstructure of pork muscle fiber was observed by scanning electron microscopy during storage at 4 ℃. The results showed that the microbial load, pH, TVB-N content and TBARS value of pork increased with storage time, while the total sugar content, L* value, a* value, hardness and chewiness decreased. Microbial growth during the storage of meat caused changes in the structure of muscle fibers. The change in the physicochemical quality pork was correlated with the species and growth rate of microorganisms on it, and the spoilage capacity of B. thermosphacta was higher than that of P. fluorescens. The correlation analysis showed that the total bacterial count, pH, total sugar content, TVB-N content and TBARS value were closely related to storage time, among which the total bacterial count had the highest correlation with storage time and therefore could be used as an indicator for quality evaluation and shelf life prediction.