The impact of muscle and aging time on meat tenderness in the carcasses of Limousin x Holstein-Friesian crossbred bulls

The impact of muscle and aging time on meat tenderness in carcasses of Limousin x Holstein-Friesian bulls was evaluated. The scope of the research covered measurement of pH, basic composition, total collagen, shear force (WBSF), myofibrillar fragmentation index (MFI), and analysis of proteins with the use of SDS-PAGE electrophoresis. The results underline the strong relationship between the chemical composition and collagen content of meat and its tenderness. The MFI as an index of advancement of the myofibrillar degradation process showed a high correlation with the instrumentally estimated shear force. In all muscles, a decrease of desmin, troponin T (TnT) and an increase of TnT derived polypeptides during aging were observed. The highest decrease of TnT together with the decrease WBSF in Semitendinosus (ST) muscles during aging resulted from a more extensive proteolysis in this muscle. The results indicate the relationship between the activity of selected proteins and the shear force, which may lead to a more effective prediction of meat tenderness. Practical applicationsBeef aging is an important process of preparing beef for consumption. Based on the results presented in this paper one may state that the phenomenon of bovine meat (Limousin x Holstein-Friesian crossbred bulls) tenderness during post mortem aging is considerably related to the quality and quantity scope of changes on myofibrall proteins, mainly desmin, troponin T and proteins with molecular weight of 32-27 kDa. The obtained results proved that meat tenderness and proteolytic changes during aging are related to the type of muscle, its function and location in the carcass. The results show a strong relationship between the activity of selected proteins and shear force value, which confirms by high correlation coefficients. Analysis of muscle proteins during aging is necessary to understand the biological basis of changes in meat tenderness and their differences among muscles. The information available in the current study should be very useful to the meat industry for prediction of beef quality especially beef tenderness during the aging process.