Strip loins (longissimus thoracis et lumborum) from bulls with normal ultimate pH (NOR, pHu 5.7), and steers were compared after storage at 15°C. HI samples had higher shear forces 120 hours post‐slaughter than NOR and steer samples (P< 0.05). Calpastatin and μ‐calpain activities were higher in the NOR bulls than in steers, but the rates of decline in these activities were more rapid in NOR samples. The activity of μ‐calpain was low at all times and appeared to be involved in the increased toughness of the HI samples. The activity of m‐calpain and the calpastatin : μ‐calpain activity ratio provided a good prediction of shear force 120 hours post‐slaughter in the strip loin (R2=0.70;P< 0.001). This suggests that calpastatin, μ‐calpain, and m‐calpain all play a role in tenderisation and that on‐farm and pre‐slaughter management rather than post‐slaughter treatment need to be used to decrease the incidence of high pH meat.
展开▼
机译：在15°C下储存后，比较了来自正常极限pH值（NOR，pHu5.7）的公牛和公牛的腰部（longissimus thoracis et lumborum）。 HI样品在屠宰后120小时的剪切力高于NOR和转向样品（P<0.05）。NOR公牛的钙帕帕抑素和μ钙蛋白酶活性高于公牛，但这些活性的下降速度在NOR样本中更快。μ钙蛋白酶的活性一直很低，似乎与HI样品韧性的增加有关。m-钙蛋白酶活性和钙蛋白酶活性：μ-钙蛋白酶活性比可以很好地预测条状里脊肉屠宰后120小时的剪切力（R2=0.70;P<0.001）。这表明钙蛋白酶、μ钙蛋白酶和间钙蛋白酶都在嫩化中发挥作用，需要使用农场和屠宰前管理而不是屠宰后处理来降低高 pH 值肉的发生率。
展开▼
