Effect of Blade Size for Mechanically Tenderizing Beef Rounds

Nine inside beef rounds of USDA Good grade were divided into thirds and randomly assigned to one of three treatments: control (c), mechanically tenderized with 1.9 mm blades (1.9) and mechanically tenderized with 3.2 mm blades (3.2). Raw and cooked proximate composition, thaw and cooking loss percentage, Instron Warner-Bratzler Shear (WBS) values, and sensory panel evaluations were determined. Steaks were oven-roasted to an internal temperature of 70°C. No significant differences (P<0.05) due to mechanical tenderizing or between 1.9 and 3.2 treatments for raw proximate analysis, thaw loss, cooking loss, WBS yield peak force and distance or sensory juiciness and flavor were demonstrated. A highly significant (P<0.01) improvement in tenderness was found due to mechanically tenderizing. The 3.2 mm blade treatment was found to have significantly higher initial and overall tenderness scores than the 1.9 mm blade treatment. The 3.2 mm blades are recommended as they improve tenderness and at the same time may provide additional strength to prevent occassional bent needles.