Phosphofructokinase mainly affects glycolysis and influences meat quality in postmortem meat

The aim of this study was to evaluate the comparative effects of hexokinase (HK), phosphofructokinase (PFK) and pyruvate kinase (PK) on glycolysis in postmortem meat. Three specific inhibitors were respectively added to postmortem lamb to produce a HK inhibition (HKI) group, a PFK inhibition (PFKI) group and a PK inhibition (PKI) group. Meat samples that assigned to these three groups and a control (CON) group were stored at 4 °C for 5 d. The results indicated that the activity of HK, PFK and PK were effectively restrained during storage. PFK activity was significantly correlated with lactate content (P < 0.05), but HK and PK activity showed a weak relationship with lactate content (P > 0.05). The myofibrillar fragmentation index of the PFKI and PKI groups were significantly lower than that of the CON and HKI groups (P < 0.05). The degradation levels of troponin T and desmin were the smallest in the PFKI group. The result of the myoglobin spectrum at 540 nm and 580 nm showed a decreasing level of oxymyoglobin after HK, PFK and PK inhibition. In conclusion, PFK showed a more dominant effect on glycolysis than HK and PK in postmortem muscle, which may provide a targeted strategy for meat quality regulation through glycolysis.