For many years, scientists have been pursuing research on skeletal muscle ageing both in humans and animals. Studies on animal models have extended our knowledge of this mechanism in humans. Most researchers agree that the major processes of muscle ageing occur in the mitochondria as the major energy production centres in muscle cells. It is believed that decisive changes occur at the enzymatic activity level as well as in protein synthesis and turnover ability. Deregulation of ion channels and oxidative stress also play significant roles. In particular, in recent years the free radical theory of ageing has undergone considerable modification; researchers are increasingly highlighting the partly positive effects of free radicals on processes occurring in cells. In addition, the influence of diet and physical activity on the rate of muscle cell ageing is widely debated as well as the possibility of delaying it through appropriate physical exercise and diet programmes. Numerous studies, especially those related to genetic processes, are still being conducted, and in the near future the findings could provide valuable information on muscle ageing. The results of ongoing research could answer the perennial question of whether and how we can influence the rate of ageing both in animals and humans.

For many years, scientists have been pursuing research on skeletal muscle ageing both in humans and animals. Studies on animal models have extended our knowledge of this mechanism in humans. Most researchers agree that the major processes of muscle ageing occur in the mitochondria as the major energy production centres in muscle cells. It is believed that decisive changes occur at the enzymatic activity level as well as in protein synthesis and turnover ability. Deregulation of ion channels and oxidative stress also play significant roles. In particular, in recent years the free radical theory of ageing has undergone considerable modification; researchers are increasingly highlighting the partly positive effects of free radicals on processes occurring in cells. In addition, the influence of diet and physical activity on the rate of muscle cell ageing is widely debated as well as the possibility of delaying it through appropriate physical exercise and diet programmes. Numerous studies, especially those related to genetic processes, are still being conducted, and in the near future the findings could provide valuable information on muscle ageing. The results of ongoing research could answer the perennial question of whether and how we can influence the rate of ageing both in animals and humans.

Meat tenderization is the disruption of meat structure, breaking the collagen subsequently resulting in good palatability and acceptance by consumer. Tenderization could be achieved by the traditional method of ripening for a long period in controlled temperature with due precautions to prevent meat spoilage. In this process endogenous muscle enzymes viz. calpains, cathepsins and caspases are responsible for proteolysis of muscle. Other processes adopted for tenderization include use of electricity, heat, physical force (hydrostatic pressure), ultrasonic waves, shock waves in water (hydrodyne), enzyme action, use of vitamins, ionic compounds, mineral salts, and chemical compounds. The electrical stimulus of low voltage is more popular than high voltage due to the cost involved. Like endogenous enzymes, plant based exogenous enzymes also cause tenderization, but their activity should be monitored to avoid over-tenderization. Chemicals, vitamins and ionic compounds activate the calcium-dependent proteases and lysosomal enzymes, which are responsible for tenderization.