Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: 4/22/2005
Publication Date: 5/12/2005
Citation: Bowker, B.C., Liu, M., Fahrenholz, T.M., Callahan, J.A., Vinyard, B.T., Solomon, M.B. 2005. Effect of hydrodynamic pressure processing and blade tenderization on protein characteristics in top rounds from brahman cattle [abstract]. BARC Poster Day. Paper No. 35.
Technical Abstract: Technologies such as hydrodynamic pressure processing (HDP) and blade tenderization (BT) can be utilized to improve the tenderness of inherently tough beef cuts. The mechanisms by which these technologies alter muscle proteins and ultrastructure to influence tenderness have not been fully elucidated. The objective of this study was to investigate the effects of HDP, BT, 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 on day 0 in a balanced incomplete block design. Each treatment sample had a paired control. Samples were analyzed for sarcoplasmic and myofibrillar protein solubility and the SDS-PAGE banding patterns of myofibrillar and sarcoplasmic fractions were determined and related to tenderness measurements (kg shear force). 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% compared to controls, but there was no differences among treatments. MFI was negatively correlated to day 0 (r=-0.53) tenderness measurements. Sarcoplasmic and myofibrillar protein solubility did not differ (p>0.05) between control and treated samples nor among treatments. Myofibrillar electrophoretic protein gels indicated that HDP and BT+HDP samples had higher (p<0.05) 100 kDa to actin band ratios than controls, whereas BT and control samples had similar 100 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 during BT the muscle structure is physically disrupted and that HDP tenderization may potentially be the result of both physical disruption of the muscle structure and increased proteolysis.