Woodward B W, DeNise S K, Marchello J A
Department of Animal Science, University of Minnesota, St. Paul 55108, USA.
J Anim Sci. 2000 Apr;78(4):804-9. doi: 10.2527/2000.784804x.
Calpastatin activity measured at 24 h postmortem in bovine longissimus muscle (PMLD24) is correlated with Warner-Bratzler shear force (WBS) measurements, an objective measure of tenderness. A live-animal measurement of calpastatin activity that correlates with 24-h postmortem activity would provide information for selection programs without the expense of progeny testing. The purpose of this study was to evaluate the effectiveness of calpastatin activity measurements obtained on tissue samples from live animals and to determine the relationship among various calpastatin activity measures and tenderness determined by WBS and sensory panel. Biopsies (approximately 10 g) were obtained surgically 2 d before slaughter from the supraspinatus muscle on the anterior surface of the scapula (LISH0) from contemporary purebred Angus bulls (n = 12) and steers (n = 17). Biopsies from a subset of these cattle (n = 12) were refrigerated at 4 degrees C to simulate the postmortem cooling process for 24 h (LISH24) prior to extraction. A rib section anterior to the 12 and 13th rib interface was collected from all animals at the commercial abattoir between 22 and 23 h postmortem for PMLD24, sensory panel, and WBS measurements. A postmortem shoulder muscle sample (PMSH24) was collected at the same time. Calpastatin was extracted from all muscle samples using a heated calpastatin activity protocol. Sensory panel tenderness, WBS, LISH0, LISH24, and PMSH24 were not different between bulls and steers. However, PMLD24 values were significantly different. Significant partial correlations were found between WBS and sensory panel tenderness (-.55), between WBS and PMLD24 (-.43), and between LISH24 and PMLD24 (.78). Therefore, similar calpastatin activity values are possible with ante- and postmortem tissue samples, suggesting the possibility of using measurements from live-tissue biopsies from other than the longissimus muscle to predict end product tenderness.
在牛的背最长肌中，宰后24小时测得的钙蛋白酶抑制蛋白活性（PMLD24）与Warner-Bratzler剪切力（WBS）测量值相关，WBS是嫩度的客观测量指标。与宰后24小时活性相关的活体动物钙蛋白酶抑制蛋白活性测量值，将为选择计划提供信息，而无需进行后代测试的成本。本研究的目的是评估从活体动物组织样本中获得的钙蛋白酶抑制蛋白活性测量的有效性，并确定各种钙蛋白酶抑制蛋白活性测量值与由WBS和感官评定小组确定的嫩度之间的关系。在屠宰前2天，从当代纯种安格斯公牛（n = 12）和阉牛（n = 17）肩胛前表面的冈上肌手术获取活检样本（约10克）（LISH0）。这些牛中的一部分（n = 12）的活检样本在4℃冷藏，以模拟宰后冷却过程24小时（LISH24），然后进行提取。在商业屠宰场，在宰后22至23小时从所有动物收集第12和13肋界面前方的肋骨部分，用于PMLD24、感官评定小组和WBS测量。同时收集宰后肩部肌肉样本（PMSH24）。使用加热的钙蛋白酶抑制蛋白活性方案从所有肌肉样本中提取钙蛋白酶抑制蛋白。公牛和阉牛之间的感官评定小组嫩度、WBS、LISH0、LISH24和PMSH24没有差异。然而，PMLD24值有显著差异。在WBS和感官评定小组嫩度之间（-.55）、WBS和PMLD24之间（-.43）以及LISH24和PMLD24之间（.78）发现了显著的偏相关。因此，宰前和宰后组织样本可能具有相似的钙蛋白酶抑制蛋白活性值，这表明使用来自背最长肌以外的活体组织活检测量值来预测最终产品嫩度的可能性。
