Submitted to: Journal of Muscle Foods
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/4/2006
Publication Date: 1/10/2007
Citation: Bowker, B.C., Liu, M., Solomon, M.B., Eastridge, J.S., Fahrenholz, T., Vinyard, B.T. 2007. Effects of hydrodynamic pressure processing and blade tenderization on intramuscular collagen and tenderness-related protein characteristics of top rounds from Brahman cattle. Journal of Muscle Foods 18(1):35-55. Interpretive Summary: Hydrodynamic pressure processing (HDP) and blade tenderization (BT) enhance meat tenderness, but the mechanisms by which they tenderize are not fully understood. Since beef tenderness is determined primarily by the intramuscular connective tissue and integrity of muscle proteins, top rounds from Brahman cattle were treated by BT, HDP, and BT followed by HDP (BT+HDP) and their influence on collagen and muscle protein characteristics were evaluated. BT increased myofibril fragmentation, but did not affect collagen, protein solubility, or muscle protein profiles indicating that BT tenderizes through the physical disruption of the muscle structure. HDP and BT+HDP shifted muscle protein profiles as well as increased myofibril fragmentation and collagen solubility. Thus, in addition to the physical disruption to the muscle structure, HDP may influence tenderness through direct alterations of muscle proteins and connective tissue.
Technical Abstract: This study evaluated the effects of blade tenderization (BT), hydrodynamic pressure processing (HDP), and BT followed by HDP (BT+HDP) on collagen solubility and tenderness-related protein characteristics in top rounds from Brahman cattle. Top rounds (n=12) were divided in half and randomly assigned to HDP, BT, or BT+HDP with each treatment sample having a paired control. HDP and BT+HDP increased (P<0.0001) collagen solubility, but the correlation between percent soluble collagen and tenderness was low (r = -0.41). All three treatments increased (P<0.01) fragmentation of myofibrils 35 percent compared to controls. HDP and BT+HDP treatments increased (P<0.05) the content of a 100-110 kDa protein observed in myofibrillar protein fractions by SDS-PAGE. Minimal treatment differences were observed in sarcoplasmic proteins using SDS-PAGE. Results suggest BT physically disrupts the muscle structure to improve tenderness while HDP tenderization potentially results from both physical disruption of the muscle structure and some form of direct alterations to muscle proteins.