Abstract:The effects of hypoxia inducible factor-1α (HIF-1α) mediating proline hydroxylase domain (PHD) on glycolysis activity and color stability of yak meat after slaughter were investigated. The longissimus dorsi muscle of yak was treated with dimethyloxalylglycine (DMOG) and Lificiguat (YC-1). The effects of PHD on color stability of postmortem yak meat were investigated by measuring PHD activity, a* value, related enzyme activity, mitochondrial function and Mb characteristics. The results were as follows: compared with the control group, LDH activity, MRA, NADH content, OMb content and MMb content in DMOG group were significantly increased from 6h to 72h (P<0.05), while PHD activity, mitochondrial membrane potential, DMb content and NAD+ content in DMOG group were significantly decreased (P<0.05). Meanwhile, the Mb secondary structure stability of DMOG group was higher than that of control group, and the effect of YC-1 group was opposite to that of DMOG group. In conclusion, HIF-1α mediated PHD reduced NADH content and prevented MMb from being reduced to OMb by down-regulating LDH and MRA activities and affecting mitochondrial function. Therefore, HIF-1α mediated PHD to reduce NADH content by down-regulating LDH and MRA activities and affecting mitochondrial function, so that MMb cannot be reduced to OMb. At the same time, this pathway would also reduce the stability of Mb secondary structure, and eventually lead to reduced meat color stability, and meat color deterioration. The research investigated the differences in meat quality during postmortem aging of yak meat at different altitudes and the relationship between hypoxic factor HIF-1α release and meat quality.