Fresh pork undergoes rapid biochemical changes after slaughter, as muscle tissue depletes its energy reserves, leading to quality deterioration. Researchers have now demonstrated that applying an electrostatic field (EF) during controlled freezing-point storage can mitigate this process at the molecular level. The treatment preserved glycogen and adenosine triphosphate (ATP), reduced lactate accumulation, and modified the structure of soluble muscle proteins, according to a study published in Food Quality and Safety (DOI: 10.1093/fqsafe/fyag047).
Postmortem glycolysis is a major culprit in meat quality loss, where glycogen converts to lactate, dropping pH and causing pale, soft, and exudative meat with poor water-holding capacity. While conventional refrigeration slows this, near-freezing storage offers better preservation but demands precise temperature control. Electrostatic-field technology has previously shown promise in improving water distribution, but its impact on metabolic pathways remained unclear.
The research team, 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 a comprehensive study. They stored pork muscle 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. Over 120 hours postmortem, they tracked energy metabolites, glycolytic enzyme activities, and protein structural changes.
Results showed that EF-treated pork had 17.5% less lactate than conventionally refrigerated samples at 120 hours, while glycogen and ATP consumption were 14.9% and 37.3% lower, respectively. The treatment also preserved more pyruvate and reduced Na⁺/K⁺-ATPase activity. Notably, protein aggregates formed early but became smaller and more ordered from 36 to 120 hours. Enzyme modifications shifted, with reduced phosphorylation and increased acetylation, aligning with slower glycolytic activity.
The authors emphasize that the preservation effect is not just from colder temperatures but from the EF's influence on the molecular environment, altering enzyme conformation and regulatory modifications. The time-dependent protein restructuring offers a mechanistic explanation for the reduced conversion of pyruvate to lactate and better ATP retention.
These findings provide a foundation for developing EF-assisted cold storage in fresh meat supply chains. By slowing pH decline and conserving ATP, the technology could help maintain water-holding capacity, texture, appearance, and overall quality during processing and transport. The low-power 30-watt system also suggests energy efficiency, though commercial benefits were not directly tested.
Future research should validate the causal link between protein structural changes and enzyme modifications, possibly through molecular dynamics simulations. Larger studies are needed to assess microbial safety, sensory quality, shelf life, and equipment scalability before industrial adoption.
