Effects of electrostatic field combined with controlled freezing-point storage on glycolysis in fresh pork

This study investigated the effects of electrostatic field (EF) combined with controlled freezing-point storage on glycolysis in pork. Muscle samples (longissimus dorsi) from pig carcasses were assigned to different storage conditions: conventional refrigeration storage (Con group), controlled freezing-point storage (Fre group) and 12 kV EF combined with controlled freezing-point storage (Ele group). The results indicated that EF treatment increased particle size and decreased zeta potential of sarcoplasmic proteins compared with the Con (4 ± 0.5 ℃) and Fre (-1 ± 0.5 ℃) groups during early storage (1.5-24 h postmortem), whereas EF treatment led to a smaller particle size, higher zeta potential and tighter secondary structure in the Ele group at 36-120 h postmortem. Samples in the Ele group had higher glycogen, pyruvate, and ATP contents, while lower lactate content and Na+/K+-ATPase activity than those in the Con and Fre groups. At 120 h postmortem, lactate content in the Ele group was 17.5% lower than that in the Con group; glycogen and ATP consumption in the Ele group were approximately 14.9% and 37.3% lower than those in the Con group. Glycolytic enzyme phosphorylation levels in the Ele group were lower, and the acetylation levels were higher compared with those in the Con and Fre groups. Therefore, EF treatment may delay the process of glycolysis and improve meat quality by regulating the phosphorylation and acetylation levels of key glycolytic enzymes (triosephosphate isomerase (TPI), lactate dehydrogenase (LDH), and pyruvate kinase (PK)) and the structure of sarcoplasmic protein.