关键词: 猪肉, 静电场, 冰温, 糖酵解酶, 翻译后修饰

Abstract: This study investigated the quality and preservation mechanisms to explore the effects of electric field-assisted controlled freezing point storage on postmortem pork quality and glycolytic key enzyme activities. The longissimus dorsi muscles from pig carcass were assigned into different storage conditions: conventional refrigeration storage (4℃), controlled freezing point storage (-1±0.5℃), 4 kV electric field-assisted controlled freezing point storage (-1℃+4 kV) and 12 kV electric field-assisted controlled freezing point storage (-1℃+12 kV). The quality parameters, activities of glycolytic key enzymes, and sarcoplasmic protein phosphorylation/acetylation were analyzed. The results showed that the pH value of samples in the 12 kV electric field-assisted controlled freezing point storage group was significantly higher than that of the 4°C group and -1°C group at 72 h postmortem. The cooking loss of the 12 kV electric field-assisted controlled freezing point storage group was significantly lower than that of the 4°C, -1°C and 4 kV electric field-assisted controlled freezing point storage groups during 6 ~36 h postmortem. At 36 h and 120 h postmortem, the shear force of the 12 kV electric field-assisted controlled freezing point storage group was significantly lower than other treatment groups. During 36 ~120 h postmortem, the activities of glycogen phosphorylase, lactate dehydrogenase, and pyruvate kinase in all experimental groups （4°C group, -1°C group, and 12 kV electric field-assisted controlled freezing-point storage） exhibited decreasing trends. Notably, the enzyme activities in the 12 kV electric field-assisted controlled freezing-point storage group remained lower than those in both 4°C and -1°C groups during 36 ~120 h postmortem. At 72 hours postmortem, the phosphorylation and acetylation levels of sarcoplasmic proteins in the 12 kV electric field-assisted controlled freezing point storage group were significantly lower than those in the 4°C and -1°C groups. In conclusion, compared with non-electric field treatments, 12 kV electric field-assisted controlled freezing point storage significantly delayed pH decline rate, decreased cooking loss and improved tenderness. And 12 kV electric field treatment alleviates quality deterioration during storage, potentially through modulating post-translational modifications of glycolytic key enzymes to regulate their activities, thereby delay the deterioration of meat quality.

Key words: pork, electric field, controlled freezing point storage, glycolytic enzyme, post-translational modification