Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: September 15, 2009
Publication Date: April 1, 2010
Citation: Bowker, B.C., Eastridge, J.S., Paroczay, E.W., Callahan, J.A., Solomon, M.B. 2010. Aging/tenderization mechanisms. In: Toldra, F., editor. Handbook of Meat Processing. Ames, IA: Wiley-Blackwell. p. 87-104.
Postmortem aging of meat is an effective postharvest technique for improving meat tenderness. Improvements in tenderness when meat is stored at refrigerated temperatures for an extended time postmortem are due to changes in the muscle ultrastructure brought on by the degradation of key myofibrillar and cytoskeletal proteins. While it is widely accepted that this postmortem proteolysis is the result of endogenous enzymes within the muscle, the enzyme systems involved and the underlying mechanisms controlling them have been the subject of much debate. The objective of this book chapter is to provide an overview of the established theory of enzymatic aging tenderization and to review recent developments that contribute to a more complete understanding of the underlying mechanisms that influence postmortem proteolysis and the aging tenderization of meat. The calpain, cathepsin, and proteasome enzyme systems are discussed in regards to their potential contributions to aging tenderization. The potential roles that apoptosis, caspase enzymes, heat shock proteins, and antemortem factors play in postmortem proteolysis are also discussed. This chapter also explores intrinsic muscle factors and potential non-enzymatic mechanisms that may contribute to the aging tenderization process. Finally, this chapter discusses the emerging use of proteomic approaches to understanding the underlying mechanisms of aging tenderization.