Quality grade, portion size, needle tenderization and cookery method effects on cooking characteristics and palatability traits of portioned strip loin and top sirloin steaks

Strip Loin (IMP # 1180A) and Top Sirloin Center Cut steaks (IMP # 1184B) purchased from a foodservice purveyor and aged 21 days were used to evaluate cookery method, needle tenderization, quality grade and portion size effects on palatability and cooking characteristics. Both steak types were distributed across 4 quality grade classes (USDA Select = S, USDA Choice = C, USDA Prime = P, and Certified Angus Beef = UC), 2 portion sizes (strip loins, 283 and 397 g; top sirloins, 255 and 340 g), 2 tenderization treatments (needle tenderized = T and nontenderized = NT) and 2 cooking methods (Clamshell broiler-grill = CS and electric grill = FW). Cook time/100 g was lower (P < 0.05) in P than C and UC strip loin steaks and lower (P < 0.05) in P than S, C and UC sirloin steaks. Shear force was lower (P < 0.05) in the UC and P strip steaks than S or C; however, there was no quality grade class effect on sirloin shear force. Cook loss and cook time were significantly higher in the larger portioned strips and sirloin steaks; however, cook time expressed on a weight constant basis (per 100 g) was not different across portion size. Shear force was lowered by needle tenderization (P<0.05) in strip loin and sirloin steaks. CS strip loin and sirloin steaks required about half as much cook time/100 g as FW steaks and shear force was lower (P<0.05) in CS strips than FW. Quality grade class did not affect (P>0.05) sensory tenderness in the strips or sirloin steaks. Sensory tenderness scores were lower (P<0.05) in the 397 g and CS strips than the 283 g and FW strips, respectively. Juiciness scores were significantly lower in the CS than FW strips. Needle tenderization did not affect (P>0.05) sensory tenderness in the strips steaks but improved sensory tenderness scores in the sirloin steaks. A needle tenderization by quality class interaction in the sirloins showed that T steaks from the S, C and UC classes were more tender than NT steaks; however, tenderization did not affect tenderness of P steaks. Collectively these data suggest that rapid cookery systems (i.e., Clamshell) can reduce cooking time in portioned foodservice strip and top sirloin steaks without detrimental effects on palatability.