Effects of electrical stimulation on metabolomic and lipidomic profiles of beef Longissimus thoracis muscle

This study evaluated the temporal changes in the metabolome and lipidome of muscle collected at various times postmortem from electrically stimulated (ES) and non-stimulated (NS) carcasses. Carcasses (n = 6 per treatment) from feedlot Nellore (Bos indicus) bulls were split and randomly assigned to either medium-voltage ES or NS treatments and Longissimus thoracis (LT) muscle samples were collected at 1 h, 3 h, 12 h and 24 h postmortem for metabolome and lipidome analyses. Temporal metabolomic and lipidomic profiling identified 829 and 466 compounds, respectively, of which 152 and 47, respectively differed between ES and NS carcasses at 1 h (n = 34 and 19, respectively), 3 h (n = 44 and 4, respectively), 12 h (n = 46 and 16, respectively) and 24 h (n = 28 and 8, respectively) postmortem. Among the numerous metabolic pathways regulating the effects of ES on early postmortem muscle metabolism, results of this study highlight the dynamic interaction between energy metabolism, cellular response to stress, and muscle structure throughout the early postmortem maturation of beef. Specifically, ES induced a distinct temporal metabolic pattern characterized by an early energy burst and acidification (0-3h), followed by oxidative adaptation and proteolysis (3-12h), and finally the stabilization and restructuring of lipids (12-24 h). These coordinated biochemical transitions suggest that ES acts as a modulator of postmortem energy flow and redox homeostasis, accelerating early metabolic adaptation and influencing lipid remodeling during postmortem muscle development.