Song Zhen, Hwang Inho
College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China.
Department of Animal Science, Chonbuk National University, Jeonju, Korea.
Anim Biosci. 2025 May;38(5):1041-1052. doi: 10.5713/ab.24.0376. Epub 2024 Oct 25.
Type I and III collagen content exert contrasting influences on meat tenderness. μ-calpain autolysis correlates with beef tenderness. Thus, the study aimed to determine the changes in these proteins.
Three hundred twenty-four Hanwoo cattle, including cows and steers, and eight muscles were evaluated for proteolysis during dry ageing period. The ratios of type I and III collagen were determined by densitometric scans of bands resolved by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE), and μ-calpain activity was determined using casein zymography. Proteins involved in proteolysis were analysed by liquid chromatography-tandem mass spectrometry.
The ratio of type I and III collagen in every muscle showed a significant difference with increasing ageing times (p<0.05). In steers, the ratio decreased with increased ageing time, and in cows, except for Biceps femoris and Diaphragm muscles, a similar trend was observed. Significant differences in the ratio of type I and III collagen were found between different muscles of cows at the same ageing time (p<0.05), but no significant differences were found in steer muscles at the same ageing time (p>0.05). Casein zymogram results showed an inverse relationship between pH values and μ-calpain autolysis in every muscle. A significant reduction in μ-calpain activity was observed in all muscles with extended ageing times, while the rate of autolysis differed greatly (p<0.05) between muscles at the same ageing time. Interestingly, electropherogram analysis showed that cow muscles had a higher μ-calpain activity than steer muscles. Ageing time significantly influenced proteolysis, with 24 proteins showing marked changes.
The ageing times significantly affect the ratio of type I and III collagen, coinciding with μ-calpain autolysis rates in steers. The ratio of type I and III collagen had a significant changes during the ageing period from cows, which may be related to the amount of collagen cross-linking.
I型和III型胶原蛋白含量对肉的嫩度有相反的影响。μ-钙蛋白酶自溶与牛肉嫩度相关。因此，本研究旨在确定这些蛋白质的变化。
对324头韩牛（包括母牛和公牛）以及8块肌肉在干腌熟化期间的蛋白水解情况进行评估。通过十二烷基硫酸钠（SDS）-聚丙烯酰胺凝胶电泳（PAGE）分离条带的光密度扫描测定I型和III型胶原蛋白的比例，使用酪蛋白酶谱法测定μ-钙蛋白酶活性。通过液相色谱-串联质谱分析参与蛋白水解的蛋白质。
随着熟化时间的增加，每块肌肉中I型和III型胶原蛋白的比例均显示出显著差异（p<0.05）。在公牛中，该比例随熟化时间增加而降低，在母牛中，除股二头肌和膈肌外，也观察到类似趋势。在相同熟化时间下，母牛不同肌肉之间I型和III型胶原蛋白的比例存在显著差异（p<0.05），但在公牛肌肉中未发现显著差异（p>0.05）。酪蛋白酶谱结果显示，每块肌肉的pH值与μ-钙蛋白酶自溶呈负相关。随着熟化时间延长，所有肌肉中的μ-钙蛋白酶活性均显著降低，而在相同熟化时间下，不同肌肉之间的自溶速率差异很大（p<0.05）。有趣的是，电泳图谱分析表明，母牛肌肉的μ-钙蛋白酶活性高于公牛肌肉。熟化时间对蛋白水解有显著影响，有24种蛋白质表现出明显变化。
熟化时间显著影响I型和III型胶原蛋白的比例，这与公牛中的μ-钙蛋白酶自溶速率一致。母牛在熟化期间I型和III型胶原蛋白的比例有显著变化，这可能与胶原蛋白交联量有关。
