荧光假单胞菌和热杀索丝菌对低温贮藏期间猪肉品质变化的影响

为研究荧光假单胞菌和热杀索丝菌与猪肉品质变化的相关性，测定了在4 ℃下贮藏猪肉的微生物菌落数、pH值、色泽（L*、a*、b*值）、质构特性、总糖含量、总挥发性盐基氮（total volatile basic nitrogen，TVB-N）值和硫代巴比妥酸反应物（thiobarbituric acid reactive substances，TBARS）值以及通过扫描电子显微镜观察猪肉肌纤维微观结构的变化。结果表明，在冷藏期间，微生物菌落数、pH值、TVB-N值、TBARS值等随着猪肉冷藏时间延长而上升，而总糖含量、L*值、a*值、硬度、咀嚼性均呈降低趋势。同时，研究发现猪肉冷藏过程中微生物的生长繁殖使其肌纤维结构发生明显变化。猪肉理化品质变化与微生物的种类和生长速率相关，热杀索丝菌的致腐败能力高于假单胞菌。相关性分析结果表明，菌落数、pH值、总糖含量、TVB-N值、TBARS值与冷藏时间密切相关，其中微生物菌落数与冷藏时间的相关性最高，可作为冷藏猪肉品质评价和货架期预测的监测指标。

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.