Effect of Energy Metabolism Regulated by AMPK Activation on Meat Color Stability of Postslaughter Yak Meat

In order to explore the effect of AMPK activation-regulated energy metabolism on meat color stability of yak meat during the maturation of yak meat, this experiment took the yak longissimus dorsi muscle as the research object, treated it with AMPK activator(AICAR) and inhibitor(Compound C), and placed it at 4 ℃ for maturation. AMPK activity, flesh color and energy metabolism related indexes were measured at the corresponding maturation time point, and the correlation analysis between flesh color and energy metabolism indexes was performed. The results showed that compared with the control group, the AMPK activity of the AICAR group increased by 13.17%, while the inhibitory group decreased by 9.03% after 12 h of maturation, indicating that AICAR had an activating effect on AMPK activity, while Compound C had a significant inhibitory effect on AMPK activity effect. With the extension of maturity time, the L^* value, a^* value and the activity of hexokinase all showed a trend of increasing first and then decreasing. The b^* value, H^* value, and lactic acid content all showed a gradual upward trends, among which L^*, b^* and H^* were always AICAR group>control group>compound C group, and a^* value was always AICAR group<control group<compound C group. During the maturation period, the pH value, creatine kinase activity and glycogen synthase activity of the three groups decreased first and then slowly increased. TMb content, OMb content, MetMbR activity glycogen content, LDH activity and NADH content showed a downward trends, while MMb content increased. When the AICAR group, compound C group and control group matured to 168 hours, their TMb content decreased by 34.52%, 31.63%, and 33.67%, respectively, and OMb content decreased by 41.38%, 40.40%, and 40.57%, respectively, MetMbR activity was only 39.74%, 42.72% and 41.41% of 6 h, while MMb content increased by 310%, 291% and 309%, respectively. From a trend point of view, the inhibition of AMPK activity could increase make NADH content, glycogen content, glycogen synthase activity, creatine kinase activity and LDH activity, and reduce hexokinase activity and lactic acid content. Correlation analysis showed that the increasing of NADH content, glycogen content, LDH activity, hexokinase activity and the decreasing of lactic acid content, creatine kinase activity, glycogen synthase activity could improve the stability of flesh color to a certain extent. Inhibition of AMPK activity could increase NADH content, creatine kinase activity and glycogen synthase activity, while reduc lactic acid content and hexokinase activity. In summary, the inhibition of AMPK activity was conducive to beneficial to the stability of the flesh color of the yak longissimus dorsi muscle during maturation. During the maturation of the yak longissimus dorsi muscle, the inhibition of AMPK activity could increase NADH content, glycogen content, LDH activity and reduce lactic acid to maintain the stability of flesh color.