电刺激对宰后牦牛肉成熟过程中肌钙蛋白-T和肌间线蛋白及嫩度的影响

Effect of electrical stimulation on Troponin-T and Desmin and tenderness of yak meat during postmortem aging

为研究电刺激对宰后牦牛肉成熟过程中Troponin-T和Desmin降解及嫩度的影响,本实验利用聚丙烯酰胺凝胶电泳(SDS-PAGE)、剪切力法及肌原纤维小片化指数法分别对比测定并动态监测宰后不同处理(电刺激、未电刺激)对牦牛的冈上肌、背阔肌和半腱肌3个部位肉在成熟0,1,2,3,5,7,14 d时Troponin-T、Desmin、剪切力及MFI影响的变化特点。结果表明:电刺激组牦牛三个部位肉Troponin-T和Desmin的降解速度和降解程度均较高,且两个处理组背阔肌Troponin-T 28 k Da、Desmin 38 k Da和36 k Da特征降解产物出现的时间较其他两个部位均早,降解程度也较高;成熟14 d后,电刺激组牦牛冈上肌、背阔肌和半腱肌的剪切力值下降百分率较未电刺激组分别显著高2.93%、9.47%、5.08%(p<0.05),但电刺激对MFI值无显著影响。由此可见,电刺激处理能显著加快宰后牦牛肉肌原纤维骨架蛋白Troponin-T和Desmin的降解程度及剪切力的下降速度,且背阔肌的宰后嫩化较其他两个部位快。

To study the effect of electrical stimulation on Troponin-T, Desmin degradation and the tenderness of the meat of yak during postmortem aging,the experiment used SDS-PAGE, shear force and myofibrillar fragmentation index method to compare and dynamic monitor the effect of different treatment （ electrical stimulation, no electrical stimulation ） on the change of characteristics of Troponin-T, Desmin, shear force and MFI of SU, LD and ST of the meat of yak during postmortem 0,1,2,3, 5,7 and 14 d.The results showed that the Troponin-T and Desmiu degradation rate and degradation degree of three parts meat of electrical stimulation group were higher, and the degradation products existed earlier than the other two parts, and degradation degree was higher than the other two parts of LD of two treatment groups.After 14 days of postmortem, the rate of decrease of the shear force of SU,LD and ST in the electrical stimulation group were increased by 2.93% ,9.47% and 5.08% in comparison with no electrical stimulation group（p 〈 0.05 ） , but the electrical stimulation had no significant effect on MFI. This showed that electrical stimulation can significantly accelerate the degradation of yak＇ s Troponin-T and Desmin and the rate of descent of shear force during postmortem aging, and tenderization speed is faster than the other two parts meat of LD during postmortem aging.