Proteomic insights into DEM-induced oxidative stress: Glycolytic and antioxidant synergy in beef colour stability

This study establishes diethyl maleate (DEM) as a novel physiologically relevant oxidative stress model for meat science, uniquely recapitulating gradual glutathione depletion during natural spoilage. Using quantitative proteomics and biochemical analyses (0-48 h postmortem), we demonstrate that DEM-induced stress paradoxically enhances beef colour stability despite accelerated glycolysis (pH 5.6 ± 0.03 at 12 h). Treated beef exhibited significantly higher redness (a*), oxymyoglobin content, NADH levels, and metmyoglobin reductase activity versus controls (P < 0.05). Proteomics revealed coordinated upregulation of key glycolytic enzymes (e.g., GAPDH, ALDOA) and redox regulator MAPK3 (293 differentially abundant proteins identified), mechanistically linking glycolytic activation to NADH-driven metmyoglobin reduction. This adaptive metabolic reprogramming stabilizes myoglobin redox states through antioxidant synergy. Our findings validate DEM's utility for simulating physiological oxidative stress and uncover an NADH-mediated preservation mechanism, providing foundational insights for discolouration-mitigation strategies.