Influence Of Caspases-3 And The Inhibitors On Yak Meat Quality Changes

Apoptosis is a programmed cell death process after the slaughter of livestock or poultry.It is closely related to meat quality. By joining the AC- DEVD – CHO, a yak meat Caspases-3 specific inhibitor, this test was aimed at detecting the changes between a variety of quality indicators after slaughter for 2h~120h.The effect of Caspases-3 on yak meat mature process and final quality was analyzed and the conclusions were shown as following:1?The influence of Caspase-3 and its inhibitors on the relationship between Caspase-3, 8and 9. after slaughter for 12 h, CK group significantly increased 118.72% in the DEVD group(p < 0.01); after slaughter for 6 h, the activity of Caspase–8 in CK group reached the maximum; after slaughter for 6 h ~ 12 h, the enzyme activity of Caspase-9 in CK group significantly increased 104.50% in the DEVD group(p < 0.01). This test shows that, the highest activity time for Caspase-3 is during 6 h-24 h after slaughter, the activity of Caspase-8is motivated a little earlier than that of Caspase-3.While, the activities of Caspase-8,9 are inhibited with the inhibition of Caspase-3 activity, thus, Caspase-3 plays an important role in the whole apoptosis pathway.2 ? The role Caspase-3 and inhibitors on the protein degradation of muscles. after slaughter for 12 h, the inhibition effect of Caspase-3 inhibitors on yak meat muscle fibrils protein degradation is remarkable. After slaughter for 120 h, the myofibril protein in DEVD group degraded in different degrees, Caspase-3 inhibitor almost has no effect. This study shows that the time for Caspase-3 to degrade protein in yak meat is around the time of 12 h. If the activity of Caspase-3 is inhibited, the degradation of muscle protein changes slowly in this process. Caspase does not dominate the protein degradation any more after slaughter for 72 h.3?The influence of Caspase-3 and inhibitors on quality. Tenderness, after slaughter for2h~120h, the shear force in DEVD group is always high compared with CK group and the difference is significant(p< 0.05). During the 2h~120h after slaughter, MFI in DEVD group was significantly lower than CK. The experiment shows that Caspase-3 does not dominant meat tenderiz after 72 h, the other endogenous enzymes began to act. With the inhibition of Caspase 3, even if there are other endogenous enzyme, yak meat tenderizer become slow after slaughter, showing that the Caspase-3 and other endogenous enzymes acted independently in meat tenderizer. Water retention and chroma. During the 2 h~120h after slaughter, the water retention of DEVD group is bad than CK group. This test shows that Caspase can significantly influence the water retention and meat color in the early 2h to 24 h after slaughter,thus the meat quality will decline if the activity of Caspase 3 was inhibited.4?Effect of Caspase-3 and its inhibitors on internal environment. After slaughter for 2 h~ 120 h, CK group reached the final pH value(pH = 5.4), which was earlier than that of DEVD group. During the 6 h to 5 d after slaughter, the glycogen content in DEVD group is lower compared with CK with the percent of 41.51%, 32.12%, 22.35% and 41.51%. This test showed that the low pH environment could be more conducive to enzyme activation of apoptosis.The energy factor. During the 2h ~ 120 h after slaughter, ATP energy value in DEVDgroup is higher than that of CK group, but it was opposite for IMP energy value and the difference was significant(p < 0.05). This showed that ATP take part in the degradation effect of Caspase. Muscle fiber ultrastructure of electron microscopy(sem). 6 h after slaughter, the muscle fiber structure is loose in CK group, and the mitochondria in cytoplasm is significantly swelling of and the muscle fiber structure in DEVD group was complete at this time; 120 h after slaughter, the muscle fiber structure in CK group was destructed seriously, Z line was broken. The muscle fiber structure in DEVD group is damaged with a low degree relatively after slaughter. This test shows that, the intracellular reaction started later in DEVD group than CK groupAnyhow, the active period of Caspase in yak meat was during 2 ~ 24 h after slaughter,which need energy supply and low pH environment. With the inhibition of Caspase activity,the ripening process become slow after slaughter. The hydrolysis of muscle fiber protein was abnormal; When the Caspase was normal, the sarcomere length eventually reduced, the area in muscle cell gap increased gradually, muscle fiber diameter decreased, pH value rose after a initial decline, glycogen content gradually reduced, color and water retention tends to be well,skeleton muscle fibril protein degraded significantly, the tender degree increased as well.Therefore, Caspase played important role in the mature process of yak meat after slaughter.