Shackelford S D, Wheeler T L, Koohmaraie M
Roman L. Hruska U.S. Meat Animal Research Center, USDA, ARS, Clay Center, NE 68933-0166, USA.
J Anim Sci. 1997 Sep;75(9):2417-22. doi: 10.2527/1997.7592417x.
The present experiments were conducted to evaluate the use of longissimus shear force at 1 or 2 d postmortem as a predictor of beef longissimus shear force at 14 d postmortem. Experiments 1 (n = 400) and 2 (n = 554) included carcasses slaughtered and processed under laboratory and commercial conditions, respectively. A carcass was classified as "tender," "intermediate," or "tough" if its longissimus shear value at 1 or 2 d postmortem was < 6 kg, 6 to 9 kg, or > 9 kg, respectively. For Exp. 1 and 2, large (P < .001) differences existed between each successive tenderness class in mean shear force at 14 d postmortem. Moreover, frequency analysis indicated that tenderness classification accurately (84.8 and 94.8% for Exp. 1 and 2, respectively) predicted whether the sample would have a "low" (< 6 kg) Warner-Bratzler shear (WBS) value at 14 d postmortem. All (100%) of the carcasses in the "tender" class had "low" WBS values at 14 d postmortem, most (81 and 85% for Exp. 1 and 2, respectively) of the carcasses in the "intermediate" class had "low" WBS values at 14 d postmortem, and most (74 and 67% for Exp. 1 and 2, respectively) of the carcasses in the "tough" class did not have "low" WBS values at 14 d postmortem. Although shear force at 2 d postmortem was only moderately correlated (r = .68) with shear force at 14 d postmortem, 68% of the carcasses sampled in Exp. 2 could be guaranteed tender with 100% accuracy based on shear force at 2 d postmortem. Thus, cooked beef longissimus shear force can be measured at 1 or 2 d postmortem and used to predict longissimus tenderness after cooler aging (14 d postmortem) with a relatively high degree of accuracy.
本实验旨在评估宰后1天或2天的背最长肌剪切力作为宰后14天牛肉背最长肌剪切力预测指标的效用。实验1（n = 400）和实验2（n = 554）分别纳入了在实验室条件和商业条件下屠宰及处理的胴体。若胴体宰后1天或2天的背最长肌剪切值分别< 6千克、6至9千克或> 9千克，则该胴体被分类为“嫩”、“中等”或“老”。对于实验1和实验2，在宰后14天，各连续嫩度等级之间的平均剪切力存在显著（P <.001）差异。此外，频率分析表明，嫩度分类能够准确地（实验1和实验2分别为84.8%和94.8%）预测样品在宰后14天是否具有“低”（< 6千克）的沃纳-布拉茨勒剪切（WBS）值。“嫩”等级中的所有（100%）胴体在宰后14天具有“低”WBS值，“中等”等级中的大多数（实验1和实验2分别为81%和85%）胴体在宰后14天具有“低”WBS值，而“老”等级中的大多数（实验1和实验2分别为74%和67%）胴体在宰后14天不具有“低”WBS值。尽管宰后2天的剪切力与宰后14天的值仅呈中度相关（r =.68），但基于实验2中宰后2天的剪切力，68%的取样胴体能够以100%的准确率保证为嫩度。因此，熟牛肉背最长肌剪切力可在宰后1天或2天进行测量，并用于以相对较高的准确度预测冷藏熟化（宰后14天）后背最长肌的嫩度。
