Submitted to: International Congress of Meat Science and Technology Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 7/13/2005
Publication Date: 8/7/2005
Citation: Bowker, B.C., Liu, M., Fahrenholz, T.M., Callahan, J.A., Vinyard, B.T., Solomon, M.B. 2005. Blade tenderization and hydrodynamic pressure processing effects on protein characteristics in top rounds from brahman cattle. In: Proceedings of the 51st International Congress of Meat Science and Technology, August 7-12, 2005, Baltimore, Maryland. Paper No. Th52. Interpretive Summary: Understanding how technologies such as blade tenderization (BT) and hydrodynamic pressure processing (HDP) tenderize tough cuts of meat is vital not only to optimize their tenderization capabilities but to also understand the biological basis for meat tenderness. Thus, top rounds from Brahman cattle were treated by BT, HDP, and BT followed by HDP (BT+HDP) and their influence on muscle protein characteristics were evaluated. All three treatments increased the degree of myofibril fragmentation, indicating a physical disruption of the muscle structure. Electrophoretic separation of muscle proteins indicated that HDP and BT+HDP samples exhibited more direct protein modifications compared to controls than BT samples. These results suggest that BT physically disrupts the muscle structure to improve tenderness while HDP tenderization may potentially be the result of both physical disruption of the muscle structure and direct alterations of muscle proteins.
Technical Abstract: The tenderness of inherently tough cuts of beef can be improved by using technologies such as blade tenderization (BT) and hydrodynamic pressure processing (HDP). It is not fully understood how these technologies alter muscle proteins and ultrastructure to influence tenderness. The objective of this study was to investigate the effects of BT, HDP, and BT followed by HDP (BT+HDP) on protein characteristics related to tenderness and protein functionality in top rounds from Brahman cattle known to be tough. Top rounds (n=12) were divided in half and assigned to either HDP, BT, or BT+HDP treatments in a balanced incomplete block design. Each treatment sample had a paired control. Samples were analyzed for myofibrillar and sarcoplasmic protein solubility and the SDS-PAGE banding patterns of myofibrillar and sarcoplasmic fractions were determined and related to tenderness measurements (Warner-Bratzler shear force, kgf). Myofibril fragmentation index (MFI) was utilized as an indicator of the breakdown of intra- and intermyofibril linkages. BT, HDP, and BT+HDP treatments increased (p<0.01) MFI approximately 35 percent compared to paired controls, but there were no differences among treatments. MFI was negatively correlated (r=-0.53) to tenderness measurements. Myofibrillar and sarcoplasmic protein solubility did not differ (p>0.05) between control and treated samples nor among treatments. Electrophoretic separation of myofibrillar proteins indicated that HDP and BT+HDP samples had higher (p<0.05) 100-110 kDa to actin band ratios than controls; whereas, BT and control samples had similar 100-110 kDa to actin band ratios. Sarcoplasmic electrophoretic protein gels exhibited minimal differences in the protein banding patterns between HDP, BT, BT+HDP, and control samples. These results suggest that BT physically disrupts the muscle structure to improve tenderness while HDP tenderization may potentially be the result of both physical disruption of the muscle structure and direct alterations of muscle proteins.