Comparative study on the postmortem proteolysis and shear force during aging of pork and beef semitendinosus muscles

Seokhee Han1, Kyung Jo1, Seul-Ki-Chan Jeong1, Hayeon Jeon1, Soeun Kim1, Minkyung Woo1, Samooel Jung1,*, Seonmin Lee1,*
Author Information & Copyright
1Division of Animal and Dairy Science, Chungnam National University, Daejeon 34134, Korea.
*Corresponding Author: Samooel Jung. E-mail:
*Corresponding Author: Seonmin Lee. E-mail:

© Copyright 2024 Korean Society for Food Science of Animal Resources. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: Apr 01, 2024 ; Revised: Apr 29, 2024 ; Accepted: May 01, 2024

Published Online: May 22, 2024


The differences in the proteolytic patterns and shear force of pork and beef during aging were evaluated. Pork and beef semitendinosus muscles were obtained at 24 and 48 h postmortem, respectively, and aged at 4°C for 0 (Day 0), 7 (Day 7), and 14 days (Day 14). Changes in the electrical conductivity were observed in pork on Day 7 and beef on Day 14. The calpain activity increased in pork (p<0.05) after 14 days of aging, whereas that of beef decreased on Day 7 (p<0.05). The cathepsin B activity in pork and beef increased between Day 7 and 14 (p<0.05). The content of α-amino group content in the 10% trichloroacetic acid (TCA)-soluble fraction increased between Day 7 and 14 in pork (p<0.05), but increased steadily in beef throughout aging (p<0.05). The electrophoretogram of the myofibrillar proteins revealed a 30 kDa protein band only in the beef lane on Day 14. The cooked pork had no significant changes in the shear force during aging periods (p>0.05), while the gradual decrease in the shear force with the increasing aging periods was shown in the cooked beef (p<0.05). Circular dichroism analysis of myosin extracts from pork and beef revealed thermal denaturation temperatures of 55 and 58°C, respectively. This study highlights the different post-mortem proteolytic patterns and thermal denaturation temperatures of myosin in pork and beef semitendinosus muscles, which contribute to distinct changes in the shear force during aging between pork and beef.

Keywords: meat aging; pork; beef; shear force; protease activity