Fresh pork quality during storage is a critical concern for the meat industry, as postmortem glycolysis leads to pH decline, protein denaturation, and moisture loss, ultimately affecting color, texture, and shelf life. A recent study published in Food Quality and Safety (DOI: 10.1093/fqsafe/fyag047) demonstrates that applying an electrostatic field (EF) during near-freezing storage can mitigate these detrimental changes at the biochemical level, offering a potential new approach to extend fresh meat shelf life.
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, investigated the effects of EF on pork muscle stored at conventional refrigeration (4°C), controlled freezing-point (−1°C), and the same near-freezing condition with a continuous 12-kV EF. They tracked metabolic changes over 120 hours postmortem, focusing on key glycolytic metabolites, enzyme activities, and protein structural modifications.
The results showed that EF-treated pork had 17.5% less lactate accumulation compared to conventionally refrigerated samples after 120 hours. Additionally, glycogen and ATP consumption were reduced by approximately 14.9% and 37.3%, respectively, indicating a slower energy depletion. The treatment also preserved pyruvate levels and lowered Na⁺/K⁺-ATPase activity, suggesting a more efficient maintenance of cellular energy.
At the protein level, the EF influenced the structure of sarcoplasmic proteins. Early in storage, proteins formed larger aggregates, but from 36 to 120 hours, they became smaller, more dispersed, and more ordered. This structural evolution was correlated with changes in post-translational modifications (PTMs) of glycolytic enzymes. Specifically, the EF tended to reduce phosphorylation and increase acetylation of lactate dehydrogenase (LDH), triosephosphate isomerase (TPI), and pyruvate kinase (PK), which are consistent with slower glycolytic activity.
“Our findings suggest that the preservation effect is not simply a consequence of keeping the meat colder,” the authors noted. “The EF appears to influence the molecular environment in which glycolytic enzymes operate, altering both protein conformation and the chemical switches that regulate enzyme activity.” This time-dependent response highlights a potential mechanism: initial protein unfolding and aggregation, followed by a more dispersed and ordered structure, leading to reduced conversion of pyruvate into lactate.
The implications for the meat industry are significant. By slowing pH decline and conserving ATP, EF-assisted cold storage could help maintain water-holding capacity, texture, and appearance during processing, transport, and retail display. The technology operates at a low power (30 watts), suggesting potential for energy-efficient preservation, though commercial benefits were not directly assessed in this study.
The authors recommend future research to validate the causal link between protein structural changes and enzyme PTMs using molecular dynamics simulations. Large-scale studies should also evaluate microbial safety, sensory quality, shelf life, equipment scalability, temperature fluctuations, operating costs, and performance across different muscle types and meat products before industrial adoption.
This research provides a mechanistic foundation for developing electrostatic-field-assisted cold storage systems, offering a promising avenue to enhance fresh meat quality and reduce waste in the supply chain.
