Cavitt L C, Sams A R
Department of Poultry Science, Texas A&M University, College Station, Texas 77843-2472, USA.
Poult Sci. 2003 Jul;82(7):1198-204. doi: 10.1093/ps/82.7.1198.
Studies were conducted to develop a non-destructive method for monitoring the rate of rigor mortis development in poultry and to evaluate the effectiveness of electrical stimulation (ES). In the first study, 36 male broilers in each of two trials were processed at 7 wk of age. After being bled, half of the birds received electrical stimulation (400 to 450 V, 400 to 450 mA, for seven pulses of 2 s on and 1 s off), and the other half were designated as controls. At 0.25 and 1.5 h postmortem (PM), carcasses were evaluated for the angles of the shoulder, elbow, and wing tip and the distance between the elbows. Breast fillets were harvested at 1.5 h PM (after chilling) from all carcasses. Fillet samples were excised and frozen for later measurement of pH and R-value, and the remainder of each fillet was held on ice until 24 h postmortem. Shear value and pH means were significantly lower, but R-value means were higher (P < 0.05) for the ES fillets compared to the controls, suggesting acceleration of rigor mortis by ES. The physical dimensions of the shoulder and elbow changed (P < 0.05) during rigor mortis development and with ES. These results indicate that physical measurements of the wings maybe useful as a nondestructive indicator of rigor development and for monitoring the effectiveness of ES. In the second study, 60 male broilers in each of two trials were processed at 7 wk of age. At 0.25, 1.5, 3.0, and 6.0 h PM, carcasses were evaluated for the distance between the elbows. At each time point, breast fillets were harvested from each carcass. Fillet samples were excised and frozen for later measurement of pH and sacromere length, whereas the remainder of each fillet was held on ice until 24 h PM. Shear value and pH means (P < 0.05) decreased, whereas sarcomere length means (P < 0.05) increased over time, indicating rigor mortis development. Elbow distance decreased (P < 0.05) with rigor development and was correlated (P < 0.01) with shear value (r = 0.2581), sarcomere length (r = -0.3079), and pH (r = 0.6303). These results suggest that elbow distance could be used in conjunction with other detection methods for optically automating measurement of rigor mortis development in broiler carcasses.
开展了多项研究，以开发一种用于监测家禽尸僵发展速率的无损方法，并评估电刺激（ES）的效果。在第一项研究中，两个试验中的每组36只雄性肉鸡在7周龄时进行处理。放血后，一半的鸡接受电刺激（400至450伏，400至450毫安，7个脉冲，每次2秒开启、1秒关闭），另一半作为对照。宰后0.25小时和1.5小时，评估胴体的肩部、肘部和翅尖角度以及肘部之间的距离。在宰后1.5小时（冷却后）从所有胴体上采集胸肉。切下肉片样本并冷冻，以便后续测量pH值和R值，每片肉片的其余部分保存在冰上直至宰后24小时。与对照组相比，电刺激处理的肉片剪切值和pH值均值显著较低，但R值均值较高（P<0.05），表明电刺激加速了尸僵。在尸僵发展过程中以及电刺激处理后，肩部和肘部的物理尺寸发生了变化（P<0.05）。这些结果表明，翅膀的物理测量可能作为尸僵发展的无损指标以及监测电刺激效果的有用方法。在第二项研究中，两个试验中的每组60只雄性肉鸡在7周龄时进行处理。在宰后0.25小时、1.5小时、3.0小时和6.0小时，评估胴体的肘部之间距离。在每个时间点，从每个胴体上采集胸肉。切下肉片样本并冷冻，以便后续测量pH值和肌节长度，每片肉片的其余部分保存在冰上直至宰后24小时。随着时间推移，剪切值和pH值均值（P<0.05）下降，而肌节长度均值（P<0.05）增加，表明尸僵在发展。随着尸僵发展，肘部距离减小（P<0.05），并且与剪切值（r=0.2581）（P<0.01）、肌节长度（r=-0.3079）和pH值（r=0.6303）相关。这些结果表明，肘部距离可与其他检测方法结合使用，以光学方式自动测量肉鸡胴体的尸僵发展情况。
