title: Effect of post-mortem storage on Ca(++)-dependent proteases, their inhibitor and myofibril fragmentation.
abstract: Post-mortem changes in two calcium-dependent proteases, their inhibitor, myofibril fragmentation index (MFI) and collagen (amount and solubility) were studied. Whereas the activity of high Ca(++)-requiring calcium-dependent protease (CDP-II) remained nearly constant throughout post-mortem storage, there was a progressive decrease in the activities of low Ca(++)-requiring calcium-dependent protease (CDP-I) and their specific inhibitor, with the inhibitor being the most susceptible to post-mortem storage. Results indicated that the greatest changes in MFI occur within the first 24 h of post-mortem storage. There were no detectable changes in either total or soluble collagen content with post-mortem storage. Hence, it was concluded that improvement in tenderness resulting from post-mortem storage must be derived from changes in the myofibrils and since CDP-I activities paralleled the myofibrillar changes, it seems reasonable to suggest that CDP-I, not CDP-II, plays an important role in the fragmentation of myofibrils and consequently in improvement of meat tenderness resulting from post-mortem storage.
authors: US Department of Agriculture, Clay Center, NE 68933, USA.
authors: M
authors: M
authors: Koohmaraie
authors: S C
authors: SC
authors: Seidemann
authors: J E
authors: JE
authors: Schollmeyer
authors: T R
authors: TR
authors: Dutson
authors: J D
authors: JD
authors: Crouse