Papinaho P A, Fletcher D L, Buhr R J
Department of Poultry Science, University of Georgia, Athens 30602, USA.
Poult Sci. 1995 Sep;74(9):1533-9. doi: 10.3382/ps.0741533.
Two experiments were conducted to determine the effects of electrical stunning and peri-mortem muscle activity (struggle in and around the time of slaughter) on post-mortem biochemical reactions in broiler breast muscle (Pectoralis major). Broilers were stunned with either 50 or 125 mA or were killed without stunning. In Experiment 1 (n = 273), broilers were either physically restrained to reduce struggling during slaughter or were unrestrained and allowed to struggle freely. Breast mean pH and R-value (ratio of adenosine to inosine nucleotides) were determined at 15 min and 24 h post-mortem, and Allo-Kramer shear was determined on 48 h post-mortem cooked meat samples from muscles excised at 15 min or 24 h. In Experiment 2 (n = 65), the breast muscle was unilaterally denervated by surgically severing the Pectoralis nerve on one side and performing a sham operation on the contralateral side. Results indicated that physical restraint resulted in higher muscle pH and lower R-values at 15 min post-mortem in the unstunned birds and birds stunned at 50 mA, but had no effect on breast meat from birds stunned at 125 mA. There were no treatment effects on meat tenderness or 24-h post-mortem pH or R-values. Stunning amperage had no effect on denervated muscle pH at 15 min post-mortem, but did affect the sham-operated muscle pH and R-values as in Experiment 1. These results indicate that the main effect of electrical stunning on early rigor development may be due primarily to inhibition of peri-mortem struggle.
进行了两项实验，以确定电击晕和宰前肌肉活动（屠宰时及屠宰前后的挣扎）对肉鸡胸肌（胸大肌）宰后生化反应的影响。肉鸡分别用50或125毫安电流电击晕或不电击晕直接宰杀。在实验1（n = 273）中，肉鸡在屠宰时要么被物理束缚以减少挣扎，要么不束缚任其自由挣扎。在宰后15分钟和24小时测定胸肌平均pH值和R值（腺苷与肌苷核苷酸的比率），并在宰后48小时对在15分钟或24小时切除的肌肉制成的熟肉样品进行Allo-Kramer剪切力测定。在实验2（n = 65）中，通过手术切断一侧的胸肌神经并对另一侧进行假手术，使胸肌单侧去神经支配。结果表明，物理束缚导致未电击晕的鸡和用50毫安电击晕的鸡在宰后15分钟时肌肉pH值较高，R值较低，但对用125毫安电击晕的鸡的胸肉没有影响。对肉的嫩度、宰后24小时的pH值或R值没有处理效应。电击晕电流强度对宰后15分钟去神经支配肌肉的pH值没有影响，但对假手术侧肌肉的pH值和R值有影响，如同实验1中那样。这些结果表明，电击晕对早期尸僵发展的主要影响可能主要是由于抑制了宰前的挣扎。
