The fact that many myofibrils are arranged in register across the muscle fibers leads to more strength for muscle and decreases muscle tenderness.
Variation in beef tenderness may be attributed to breed (genetic status), carcass composition, and environmental factors (chronological age, time on feed, implants and ante-mortem stress). The three factors that determine meat tenderness are background toughness, the toughening phase and the tenderization phase. While the toughening and tenderization phases take place during the post-mortem storage period, background toughness exists at the time of slaughter and does not change during the storage period.
The tenderization process is estimated to begin soon after slaughter (perhaps as soon as 3 h, but it is highly variable among individual carcasses).
Current evidence suggests that proteolysis of key myofibrillar proteins is the cause of meat tenderization. These proteins are involved in:
*Inter-myofibril linkages (e.g., desmin and vinculin),
*Intra-myofibril linkages (e.g., titin, nebulin, and possiblytroponin-T),
*Linking myofibrils to sarcolemma by costameres (e.g. vinculin and dystrophin), and
*The attachment of muscle cells to the basal lamina (e.g. laminin and fibronectin).
The function of these proteins is to maintain the structural integrity of myofibrils.
Meat tenderness
