Influence of myosin heavy- and light chain isoforms on early postmortem glycolytic rate and pork quality

This study addressed the influence of the content of myosin heavy- (MHC) and light chain (MLC) isoforms on early postmortem glycolytic rate and meat quality traits in the porcine longissimus muscle. The fast-glycolysing group showed lower contents of MHC slow and MLC 1s isoforms (P < 0.05), and higher MHC fast isoform contents than the normal-glycolysing group (P < 0.05). The MHC fast/slow ratio was correlated with lactate content (r = 0.41) and early postmortem muscle pH (r = -0.51), and the content of the MLC 1s isoform was negatively correlated with lactate content and glycolytic potential (r = -0.38 and -0.36, respectively). Hence, both the MHC and MLC isoforms did influence metabolite contents, thus also affecting glycolytic rate, and suggested that the myosin isoforms, in particular the MHC isoforms, might also have some bearing on the extent of protein denaturation and pork quality during the early postmortem period.