Fresh pork quality during refrigerated transport and storage could be significantly improved by applying an electrostatic field (EF) during near-freezing storage, according to new research published in Food Quality and Safety. 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 the combined treatment slows the biochemical processes that lead to meat deterioration after slaughter.
Postmortem glycolysis is a major factor in meat quality loss, as muscle glycogen is converted to lactate, causing pH to drop and leading to pale, soft, and exudative meat with poor water-holding capacity. While conventional refrigeration slows this process, storage near the freezing point offers better preservation but requires precise temperature control. Electrostatic-field technology has emerged as a promising method to enhance near-freezing storage, 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 °C, controlled freezing-point storage at −1 °C, and the same near-freezing conditions with a continuous 12-kV electrostatic field. They tracked changes in energy metabolites, glycolytic enzymes, and sarcoplasmic protein structure over 120 hours postmortem.
Results showed that pork treated with the electrostatic field contained 17.5% less lactate than conventionally refrigerated samples at 120 hours, while glycogen and ATP consumption were reduced by 14.9% and 37.3%, respectively. The treated samples also retained more pyruvate and exhibited lower Na⁺/K⁺-ATPase activity. Protein analysis revealed that early exposure promoted larger aggregates, but from 36 to 120 hours, proteins became smaller, more dispersed, and more ordered. Additionally, post-translational modifications on key glycolytic enzymes—lactate dehydrogenase, triosephosphate isomerase, and pyruvate kinase—were altered, with the treatment generally reducing phosphorylation and increasing acetylation, consistent with slower glycolytic activity.
These findings indicate that the preservation effect is not solely due to lower temperature but involves the electrostatic field's influence on the molecular environment of glycolytic enzymes, affecting both protein conformation and regulatory modifications. The time-dependent response is particularly notable: proteins initially unfolded and aggregated, then became more dispersed and structurally ordered during prolonged treatment, which may explain the reduced conversion of pyruvate to lactate and better energy retention.
This research provides a mechanistic foundation for developing electrostatic-field-assisted cold storage in fresh meat supply chains. By slowing pH decline and conserving ATP, the technology could help protect water-holding capacity, texture, appearance, and overall quality during processing, transport, and retail display. The low-power 30-watt system also suggests potential for energy-efficient preservation, though commercial benefits were not directly assessed.
Future research should validate the causal link between protein structural changes and enzyme post-translational modifications, including through 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).
