Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 16, 1998
Publication Date: N/A
Interpretive Summary: The U.S. beef industry urgently needs a technology to segregate beef by tenderness in order to gain competitive advantages and provide the consumer with more choices of quality meat. To achieve this goal, we need to understand the fundamental properties of raw meat and their relationship with postmortem treatments and cooking. The purpose of this research was to study the tensile properties of raw meat in relation to aging and tenderness. Based on the muscle structures and the data from a previous study, we proposed a mathematical model to describe the various behaviors of two bovine muscles in tension. We found that the model parameters were related to aging and that the elasticity or the initial slope of the tensile curve can be used as a measure of aging in meat. Further, the model parameters were also related to tenderness as measured by the Warner-Bratzler shear tester, a standard device recommended by American Meat Science Association. These results indicate that tenderness can be predicted from the tensile behavior of meat using the proposed model. This model may also be used to study the structural changes in meat during postmortem aging and cooking. The research should benefit the beef industry and USDA/AMS in developing a technique to predict meat tenderness.
Technical Abstract: Rheological characterization of the tensile behavior of meat is important for understanding tenderness and the changes in muscle structures during aging and cooking. This paper has provided a brief review on some basic structural features of muscle and previous research on the mechanical properties of meat. A nonlinear rheological model was proposed, which consists of both linear and nonlinear elastic elements and a viscous element. The model was used to fit the tensile data from a previous study (Lu et al., 1998) for longissimus dorsi (LD) and semitendinosus (ST) muscles. Results showed that the nonlinear model was able to fit the tensile curves of different patterns with an average root of mean square error of 0.998 kPa for LD and 4.303 kPa for ST. The elasticity of the linear spring, E, was significantly (p<0.01) affected by aging for both muscles. The effect of aging on the remaining three parameters was not significant for LD and was significant (p<0.05) for ST. Model parameters were related to tenderness measurements with the best correlation coefficient of 0.578 for LD and 0.336 for ST. This rheological model can be used to quantify the changes in muscle fibers and connective tissue during postmortem aging and cooking.