电刺激和延迟冷却对宰后牛肉肌原纤维Troponin-T降解的影响

Effect of electrical stimulation and delay chilling on the degradation of the Troponin-T from myofibrillar in the post slaughter beef

为了探讨牛肉嫩化的机理,选择24头24月龄,体重约500kg杂交牛(鲁西黄牛×西门塔尔)随机分成4组,在宰前或宰后分别进行以下4种处理:常规预冷组,延迟冷却组,电刺激处理组,电刺激和延迟冷却处理组。用SDS-PAGE和蛋白免疫印迹的方法比较分析了4种处理牛肉成熟1,3,7,10d其肌原纤维骨架蛋白Troponin-T的降解情况。结果表明:与常规冷却组相比,电刺激处理在1、3、7d时显著加快了Troponin-T的降解,而10d时差异不显著;延迟冷却处理在1、3d时显著加快了Troponin-T的降解,而7、10d时差异不显著;1、3d时延迟冷却对Troponin-T的降解影响比电刺激显著,而7、10d时则是电刺激比较显著;电刺激和延迟冷却处理的结合对Troponin-T降解的影响比电刺激处理组、延迟冷却处理组显著。综上可见,延迟冷却、电刺激无论在速度和数量上显著加快了Troponin-T的降解,加快了牛肉成熟,缩短了成熟时间,且二者有协同作用。

In order to investigate the mechanism of the beef tenderness, 24 hybrid cattle （Chinese Yellow cattle crossed with Simental） of 24 months and 500kg were chosen to be divided into four groups and treated with four method such as conventional chilling, electrical stimulation, delay chilling, combination of electrical stimulation and delay chilling. Effects of electrical stimulation and delay chilling on the degradation of skeleton protein Troponin-T from myofibrillar were studied with SDS-PAGE and Western blotting at the aging time of 1, 3, 7,10 days. The results show that compared with conventional chilling treatment, the effects of electrical stimulation on the degradation of Troponin-T have obvious difference in 1, 3, 7 aging days, but no obvious difference in 10 aging days, while the one of delay chilling had obvious difference in 1, 3 aging days, but no obvious difference in 7, 10 aging days. The effect of the combination of electrical stimulation and delay chilling on the degradation of Troponin-T is more obvious than that of electrical stimulation or delay chilling. It can be concluded that electrical stimulation and delay chilling increase the degradation of Troponin-T not only in velocity but also in quantity, shorten the aging time and had cooperative effect.