Influence of 7-day subfreezing storage on physicochemical, nutritional, and microstructural attributes of porcine longissimus thoracis et lumborum muscle.

The effect of 7-day subfreezing storage on the physicochemical properties, nutritional composition, and microstructure of pork was investigated. After 7 days of chilling at 4°C, the meat exhibited color deterioration and the development of off-flavors. In contrast, the -12°C treatment significantly reduced the deterioration in water-holding capacity and color of samples (p < 0.05) and prevented changes in pH value. Similarly, the treatments at -12 and -18°C effectively preserved the meat's tenderness, thiobarbituric acid-reactive substances, protein solubility, and textural properties, maintaining these qualities close to those of fresh meat (p > 0.05). The nutrient content of samples stored at -12°C was comparable to those stored at -18°C (p > 0.05). Furthermore, subfreezing at -12°C was found to protect muscle integrity, promoting the formation of an elastic gel network and a homogenous muscle fiber structure. Therefore, the study concludes that 7-day subfreezing storage at -12°C can reduce protein denaturation and maintain thequality of pork, a result that is typically achieved under more extreme freezing conditions at -18°C.