Moisture enhancement and blade tenderization effects on the shear force and palatability of strip loin steaks from beef cattle fed zilpaterol hydrochloride.

Two trials investigated zilpaterol hydrochloride (ZH) feeding duration, enhancement, blade tenderization, and postmortem aging effect on Warner-Bratzler shear force (WBSF; trial 1) and consumer sensory ratings (trial 2). For trial 1, USDA Select beef strip loins were obtained from carcasses of beef steers fed ZH (6.8 g/t on 90% DM) the last 0, 20, 30, or 40 d of the feeding period. One-half of each strip loin was enhanced (110%) with a brine solution, whereas the remaining portion was not enhanced. Both pieces were portioned into steaks, which were aged 7, 14, or 21 d for WBSF analysis. For trial 2, paired USDA Select beef strip loins were obtained from carcasses of beef steers fed ZH the last 0 or 20 d of feeding. Paired strip loins were fabricated into 4 pieces and assigned to control, moisture enhanced, blade tenderized, and blade tenderized + moisture enhanced treatments. Strip loin pieces were then portioned into steaks that were aged 14 or 21 d postmortem. Consumers panelists (n = 458) indicated their like or dislike of tenderness, juiciness, flavor, and overall like of each sample using 8-point, verbally anchored scales, as well as tenderness and overall acceptability. With exception of 20 d ZH-treated steaks, results from trial 1 indicate WBSF values decreased (P < 0.05) with enhancement. Among enhanced steaks, steaks from cattle fed ZH for 20, 30, and 40 d had greater (P < 0.05) WBSF values than controls. Among nonenhanced steaks, 20 d ZH-treated steaks had WBSF values similar to 0, 30, and 40 d ZH-treated steaks, whereas 30 and 40 d ZH-treated steaks had greater (P < 0.05) WBSF values than controls. Postmortem aging for 21 d improved (P < 0.05) WBSF values for all ZH durations when compared with 7-d aging treatments. Results from trial 2 indicate ZH feeding for 20 d had no effect on flavor scores, decreased tenderness scores (P < 0.05), and tended (P < 0.10) to decrease juiciness and overall like scores when compared with controls for steaks aged 14 d. After 21 d aging, steaks from 20 d ZH-fed cattle had reduced (P < 0.05) tenderness, juiciness, and overall like scores and tended (P < 0.10) to have decreased flavor scores when compared with controls. These results indicate enhancement improved WBSF, but was not sufficient to overcome the detrimental effect of ZH feeding duration on WBSF until steaks were aged for 21 d postmortem. Consumer scores indicate 20 d ZH feeding had no effect on overall acceptability, but decreased tenderness and tenderness acceptability scores when compared with controls.