Tenderization

Improvement of meat texture through the breakdown of muscle structure, occurring naturally during post-mortem storage and deliberately through mechanical, chemical, or enzymatic treatments. Natural tenderization during ageing is driven largely by calpains — calcium-dependent proteases, principally μ-calpain (active at micromolar Ca2+ concentrations) and m-calpain (requiring millimolar Ca2+) — which degrade key myofibrillar proteins. Similar proteolysis governs the tenderization of fish flesh and the deterioration of fish protein gels during storage. Processors also tenderize with blade or needle mechanical action, marinades, and plant enzymes such as papain and bromelain.