Targeted metabolomics to reveal muscle-specific energy metabolism between bovine longissimus lumborum and psoas major during early postmortem periods

Targeted metabolomics was applied to elucidate energy metabolites in bovine (Chinese Jinjiang yellow cattle, n = 4) longissimuss lumborum (LL) and psoas major (PM) muscles during the early postmortem period (1 h, 6 h, 12 h, and 24 h). The a* value increased significantly (P < .05) in both of LL and PM within 24 h postmortem. Compared with PM, LL had higher area percentage of type IIB fibers (48.41% vs 30.60%, P < .001) and lower proportion of type I fibers (24.98% vs 46.16%, P < .001). A total of 22 energy metabolites were successfully detected by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The principal component and hierarchical cluster analyses of these metabolites exhibited clear distinctions between LL and PM samples from different postmortem periods. Enzymic activities (lactate dehydrogenase, malate dehydrogenase, and succinate dehydrogenase), contents of pyruvate and numbers of metabolites involved in tricarboxylic acid (TCA) cycle evidenced different changes in LL and PM, which indicated distinguished metabolic patterns between them.