Department of Animal Sciences, Purdue University, West Lafayette, IN 47906, USA; College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China.
Department of Animal Sciences, Purdue University, West Lafayette, IN 47906, USA.
Food Chem. 2020 Jul 30;319:126571. doi: 10.1016/j.foodchem.2020.126571. Epub 2020 Mar 5.
This study aims to investigate the changes in mitochondrial apoptotic factors and proteolysis of two porcine muscles (psoas major - PM and longissimus dorsi - LD) during aging. Results found that during 2-168 h postmortem mitochondrial membrane permeability, mitochondrial lipid peroxidation, Ca levels were increased, while the reduction level and abundance of cytochrome c were decreased (P < 0.05) in both muscle types. Furthermore, the activation of caspase-3 along with increases in troponin-T and desmin degradation, and μ-calpain autolysis were found (P < 0.05), regardless of muscle type. PM maintained higher mitochondrial apoptotic factors, but had more intact desmin, less troponin-T degradation and less extent of autolyzed products of μ-calpain compared to LD (P < 0.05). These results indicate that the rapid onset of mitochondrial apoptosis of PM would not lead to a subsequent impact on myofibrillar protein degradation, suggesting that the mitochondrial apoptosis mediated tenderization process could be muscle-specific.
本研究旨在探讨猪的两块肌肉（腰大肌-PM 和背最长肌-LD）在衰老过程中，线粒体凋亡因子和蛋白水解的变化。结果发现，在死后 2-168 小时内，两种肌肉类型的线粒体膜通透性、脂质过氧化、Ca 水平均升高，而细胞色素 c 的还原水平和含量降低（P<0.05）。此外，caspase-3 的激活以及肌钙蛋白-T 和结蛋白降解、μ-钙蛋白酶自解的增加（P<0.05），与肌肉类型无关。与 LD 相比，PM 保持较高的线粒体凋亡因子，但具有更完整的结蛋白、较少的肌钙蛋白-T 降解和较少的 μ-钙蛋白酶自解产物（P<0.05）。这些结果表明，PM 中迅速发生的线粒体凋亡不会导致随后对肌原纤维蛋白降解的影响，这表明线粒体凋亡介导的嫩化过程可能具有肌肉特异性。
