Fresh pork begins to deteriorate almost immediately after slaughter as muscle tissue exhausts its energy reserves, leading to quality loss during distribution. A new study published in Food Quality and Safety (DOI: 10.1093/fqsafe/fyag047) reveals that applying an electrostatic field (EF) during controlled freezing-point storage can slow this process at the biochemical level. The treatment preserved more glycogen and adenosine triphosphate (ATP), limited lactate accumulation, and altered the structure of soluble muscle proteins, offering a potential new route to maintaining fresh pork quality during refrigerated transport and storage.
Postmortem glycolysis is a major driver of meat quality deterioration. As glycogen is converted into lactate, pH drops, increasing the risk of pale, soft, and exudative meat with poor water-holding capacity. Conventional refrigeration slows this process, while near-freezing storage offers better preservation but requires precise temperature control. Electrostatic-field technology has shown promise in improving water distribution and widening the usable near-freezing temperature range, but its effects on metabolic pathways and enzyme regulation were previously unclear.
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, conducted the study. They 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 EF. The team collected longissimus thoracis et lumborum muscle from eight pig carcasses and tracked samples from 1.5 to 120 hours postmortem, measuring energy metabolites, enzyme activities, and protein structure.
At 120 hours, electrostatic-field-treated pork contained 17.5% less lactate than conventionally refrigerated samples, while glycogen and ATP consumption were about 14.9% and 37.3% lower. The treated samples also retained more pyruvate and showed lower Na⁺/K⁺-ATPase activity. Early exposure promoted larger protein aggregates, but from 36 to 120 hours, proteins became smaller, more dispersed, and more ordered. Enzyme modifications changed with storage time; the treatment tended to reduce phosphorylation and increase acetylation of glycolytic enzymes, consistent with slower glycolytic activity.
“The preservation effect is not simply a consequence of keeping pork colder,” the authors noted. “The EF appears to influence the molecular environment in which glycolytic enzymes operate, changing both protein conformation and the chemical switches that regulate enzyme activity.” The time-dependent response is especially important: proteins initially unfolded and aggregated, then became more dispersed and structurally ordered during prolonged treatment, which may explain the slower conversion of pyruvate into lactate and better retention of cellular energy.
These findings provide a mechanistic foundation for developing electrostatic-field-assisted cold storage for fresh meat supply chains. By slowing pH decline and conserving ATP, the technology could help protect water-holding capacity, texture, appearance, and saleable quality during processing, transport, and retail display. The low-power 30-watt system also suggests potential for energy-conscious preservation, although commercial benefits were not directly tested in this experiment.
Future research should validate the proposed causal link between protein structural changes and enzyme post-translational modifications, including through molecular dynamics simulations. Larger studies should also assess microbial safety, sensory quality, shelf life, equipment scale-up, temperature fluctuations, operating costs, and performance across different muscles and meat products before industrial adoption.
