Department of Animal and Food Sciences, Texas Tech University, Lubbock 79409, USA.
J Anim Sci. 2010 May;88(5):1809-16. doi: 10.2527/jas.2009-2383. Epub 2010 Jan 15.
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.
两项试验研究了盐酸齐帕特罗（ZH）的喂养时间、增强效果、刀片嫩化和宰后成熟对 Warner-Bratzler 剪切力（WBSF；试验 1）和消费者感官评价（试验 2）的影响。对于试验 1，从饲喂 ZH（90% DM 上为 6.8 g/t）的肉牛胴体中获得 USDA 精选牛里脊肉条，最后 0、20、30 或 40 天。一半的里脊肉条用盐水溶液增强（110%），另一半则不增强。将每块肉切成牛排，在 WBSF 分析前分别进行 7、14 或 21 天的老化。对于试验 2，从饲喂 ZH 的肉牛胴体中获得配对的 USDA 精选牛里脊肉条，最后 0 或 20 天的饲养时间。配对的里脊肉条被制成 4 块，并分配到对照组、水分增强组、刀片嫩化组和刀片嫩化+水分增强组。然后将里脊肉块切成牛排，在宰后 14 或 21 天进行老化。458 名消费者品尝员使用 8 分制的、有语言锚定的量表来表示他们对每块样品的嫩度、多汁性、风味和总体喜好的喜欢或不喜欢程度，以及嫩度和总体可接受性。除了 20 天 ZH 处理的牛排外，试验 1 的结果表明，增强效果会降低 WBSF 值（P<0.05）。在增强的牛排中，饲喂 ZH 20、30 和 40 天的牛排的 WBSF 值高于对照组（P<0.05）。在未增强的牛排中，20 天 ZH 处理的牛排的 WBSF 值与 0、30 和 40 天 ZH 处理的牛排相似，而 30 和 40 天 ZH 处理的牛排的 WBSF 值高于对照组（P<0.05）。与 7 天的老化处理相比，21 天的宰后成熟提高了所有 ZH 持续时间的 WBSF 值（P<0.05）。试验 2 的结果表明，与对照组相比，饲喂 ZH 20 天对风味评分没有影响，但降低了嫩度评分（P<0.05），并降低了多汁性和总体喜好评分（P<0.10），14 天的牛排。经过 21 天的老化，20 天 ZH 饲养的牛的牛排嫩度、多汁性和总体喜好评分降低（P<0.05），风味评分也降低（P<0.10）。这些结果表明，增强效果提高了 WBSF，但在牛排宰后成熟 21 天之前，还不足以克服 ZH 喂养时间对 WBSF 的不利影响。消费者评分表明，20 天 ZH 喂养对整体可接受性没有影响，但与对照组相比，降低了嫩度和嫩度可接受性评分。
