Fresh pork quality during storage and transport could be improved by combining electrostatic fields with controlled freezing-point temperatures, according to new research published in Food Quality and Safety (DOI: 10.1093/fqsafe/fyag047). The study, conducted by researchers from the Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, and the College of Food Science and Engineering, Ocean University of China, demonstrates that electrostatic fields (EF) can slow the biochemical processes that lead to meat deterioration after slaughter.
Postmortem glycolysis is a key factor in meat quality loss. After an animal is slaughtered, muscle tissue continues to metabolize glycogen, producing lactate and lowering pH. This can lead to pale, soft, and exudative meat with poor water-holding capacity, diminishing color, texture, and market value. Conventional refrigeration slows these changes, but near-freezing storage offers better preservation, albeit with the need for precise temperature control. Electrostatic field technology has been explored for its ability to improve water distribution and widen the usable near-freezing range, but its effects on metabolic pathways and enzyme regulation were previously unclear.
The research team, led by scientists including those from the Chinese Academy of Agricultural Sciences, examined pork muscle stored under three conditions: conventional refrigeration at 4±0.5°C, controlled freezing-point storage at −1±0.5°C, and the same near-freezing conditions with a continuous 12-kilovolt electrostatic field. They tracked samples from 1.5 to 120 hours postmortem, measuring energy metabolites, glycolytic enzyme activity, and protein structural changes.
Results showed that pork treated with the electrostatic field had 17.5% less lactate than conventionally refrigerated samples at 120 hours. Glycogen and ATP consumption were reduced by approximately 14.9% and 37.3%, respectively. The treated samples also retained more pyruvate and exhibited lower Na⁺/K⁺-ATPase activity. The electrostatic field influenced post-translational modifications (PTMs) on key glycolytic enzymes, including lactate dehydrogenase (LDH), triosephosphate isomerase (TPI), and pyruvate kinase (PK). Specifically, the treatment tended to reduce phosphorylation and increase acetylation, consistent with slower glycolytic activity.
Protein structure analysis revealed that early exposure to the electrostatic field promoted larger protein aggregates, but from 36 to 120 hours, proteins became smaller, more dispersed, and more ordered. This time-dependent response suggests that the electrostatic field alters the molecular environment in which glycolytic enzymes operate, affecting both protein conformation and enzyme regulation.
The findings offer a mechanistic basis for developing electrostatic-field-assisted cold storage for fresh meat supply chains. By slowing pH decline and conserving ATP, this technology could help maintain water-holding capacity, texture, appearance, and overall quality during processing, transport, and retail display. The low-power 30-watt system also indicates potential for energy-efficient preservation, although commercial benefits were not directly assessed in this study.
Future research should validate the proposed link between protein structural changes and enzyme PTMs, possibly using molecular dynamics simulations. Larger studies are needed to evaluate microbial safety, sensory quality, shelf life, equipment scale-up, temperature fluctuations, operating costs, and performance across different muscles and meat products before industrial adoption. The study was supported by the National Key Research and Development Program of China (No. 2022YFD2100500).
