Koohmaraie M, Whipple G, Kretchmar D H, Crouse J D, Mersmann H J
Roman L. Hruska U.S. Meat Anim. Res. Center, U.S. Department of Agriculture, Clay Center, NE 68933.
J Anim Sci. 1991 Feb;69(2):617-24. doi: 10.2527/1991.692617x.
Postmortem proteolysis in skeletal muscle and factors affecting this process were examined in pork, lamb and beef longissimus muscles (LM) to determine the cause of differences in meat tenderness among these species. Fat thickness differed among species in the following order: pork greater than beef greater than lamb. The following patterns were observed for rate of temperature and pH decline: lamb greater than pork greater than beef and pork greater than beef greater than lamb, respectively. At 1 d postmortem, pork was the most tender, followed by beef and lamb, respectively. Between 1 and 14 d of postmortem storage, lamb LM was the most improved in tenderness, followed by beef and pork, respectively. Species did not differ (P greater than .05) in LM collagen solubility. Pork LM from fed pigs had the highest (P less than .05) level of cathepsins B + L and cystatin(s) activities, whereas no differences (P greater than .05) were observed among the species for cathepsin B activity. The lowest (P less than .01) Ca2(+)-dependent protease (CDP)-II and CDP inhibitor activities were observed in pork LM. Beef LM had the highest CDP inhibitor activity (P less than .05) but was intermediate in CDP-II activity. No differences were observed among species for CDP-I activity. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of myofibrils isolated at 0, 1 and 14 d postmortem indicated that by d 1, desmin hydrolysis was most extensive in pork muscle, followed by lamb and beef.(ABSTRACT TRUNCATED AT 250 WORDS)
研究了猪肉、羊肉和牛肉的背最长肌中死后肌肉蛋白水解作用及影响该过程的因素，以确定这些物种之间肉嫩度差异的原因。物种间的脂肪厚度按以下顺序排列：猪肉＞牛肉＞羊肉。观察到温度和pH下降速率的以下模式：羊肉＞猪肉＞牛肉和猪肉＞牛肉＞羊肉。宰后1天，猪肉最嫩，其次是牛肉和羊肉。在宰后储存1至14天期间，羊肉背最长肌的嫩度改善最大，其次是牛肉和猪肉。各物种背最长肌的胶原蛋白溶解度无差异（P＞0.05）。育肥猪的猪肉背最长肌中组织蛋白酶B+L和半胱氨酸蛋白酶抑制剂活性最高（P＜0.05），而各物种间组织蛋白酶B活性无差异（P＞0.05）。在猪肉背最长肌中观察到最低（P＜0.01）的Ca2+依赖性蛋白酶（CDP）-II和CDP抑制剂活性。牛肉背最长肌的CDP抑制剂活性最高（P＜0.05），但CDP-II活性处于中等水平。各物种间CDP-I活性无差异。对宰后0、1和14天分离的肌原纤维进行十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）表明，到第1天，结蛋白水解在猪肉肌肉中最为广泛，其次是羊肉和牛肉。（摘要截短至250字）
