U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska


Date of this Version


Document Type



Published in Beef Research Program Progress Report (1993) No. 4 (Part 1): 144-145


Many studies have evaluated changes that occur in muscle during the aging process and how they relate to meat tenderness. Other research has shown that subjecting carcasses to higher temperatures soon after slaughter speeds the aging process that ultimately results in improved tenderness. Several things may explain this effect. The higher temperature causes the pH (acidity) of the muscle to decrease faster. Also, the combination of lower pH and higher temperature could promote an earlier release of calcium into the muscle, which normally occurs in muscle tissue after slaughter. This increase in calcium concentration in turn activates the calpain enzyme system (a naturally occurring enzyme system that is found in muscle tissue). When calpain is activated by calcium, it has the potential to degrade certain muscle proteins that must be degraded for meat to be tender. A discussion of this is found in the previous article. Therefore, because meat from Bos indicus breed crosses often is less tender than meat from Bos taurus breeds, we studied whether tenderness could be altered by carcass high-temperature conditioning and, if so, what mechanisms are involved.