Quantitative transcriptomic and metabolomic analyses reveal the changes in Tibetan pork during refrigerated storage

During refrigeration, postmortem quality changes of Tibetan pork are driven by coordinated transcriptional reprogramming that induces a metabolic shift from aerobic to anaerobic metabolism and activates the key signaling pathways regulating proteolysis and cell membrane integrity. To validate this hypothesis, pork samples were stored at 4 °C for 5 days and analyzed using multi-omics approaches. Metabolomic results revealed a 52% increase in total metabolite abundance after 5 days, accompanied by substantial accumulation of lysophospholipids, indicating severe membrane structural damage. Continuous protein degradation resulted in the release of free amino acids, which subsequently promoted the accumulation of two key biogenic amines, 1,5-diaminopentane (cadaverine) and tyramine. Transcriptomic analysis identified 5062 differentially expressed genes and revealed significant activation of several pathways, including PI3K-Akt and calcium signaling, in postmortem pork. These pathways collectively mediated extensive degradation of myofibrillar and extracellular matrix proteins. Overall, these findings systematically elucidate the molecular mechanisms underlying the development of tenderness and flavor in Tibetan pork, providing a theoretical basis for improving meat quality control under cold-chain conditions.