Calpain and calpastatin activity post mortem and meat tenderness

The calpain and calpastatin proteolytic enzyme system is believed to be the main contributor to the tenderness of meat at post mortem. However, little is known about the enzyme calpain and its inhibitor calpastatin and how the two influence meat tenderness. This could be due to the fact that the study of the technology to understand calpain system is still relatively new. When factors that influence conversion of muscle to meat, meat tenderization and the activity of calpain and calpastatin are considered, it is evident that that there is overlap of the factors involved in the three aspects. However, not all factors that influence meat tenderization have been shown to affect the calpain and calpastatin enzymatic system. Thought there are studies that demonstrate how diet, growth promoters, gender, weather, handling of animals and electrical stimulation influence the calpain and calpastastin enzymatic system, these studies are not conclusive. In view of this, further studies are need particularly in South Africa to understand the system fully under local conditions and in local beef cattle breeds such as the Nguni, Africander and Bosmara. Furthermore, there is a need for work to establish the relationship between pH and the activity of calpain and calpastatins give the conflicting views held on this aspect.