Savenije B, Schreurs F J G, Winkelman-Goedhart H A, Gerritzen M A, Korf J, Lambooij E
Institute for Animal Science and Health (ID-Lelystad BV), The Netherlands.
Poult Sci. 2002 Apr;81(4):561-71. doi: 10.1093/ps/81.4.561.
The general method for stunning poultry before slaughter is by immersion of a chicken's head into an electrified waterbath. This method results in carcass and meat quality deficiencies. The major problems are hemorrhages and a delay in onset of rigor mortis, which increases the risk of cold shortening with early deboning. In two experiments, this study examines the early postmortem metabolism in the breast muscle and its effect on ultimate meat quality. The first experiment describes the effects of 5 h feed deprivation on the availability of glycogen from the liver and the breast muscle, of waterbath and head-only electrical stunning on pH and metabolite levels up to 6 h in unprocessed muscle, and the consequences on meat quality. The second experiment compares the same measurements after waterbath and head-only electrical stunning, CO2/O2/N2 and Ar/CO2 gases, and captive needle stunning. Metabolic degradation halted after 6 h without processing or after 4 h under conventional conditions after waterbath and CO2/O2/N2 stunning. With other stunning methods, this occurrence is at a faster rate, largely depending on muscle activity. Muscle glycogen does not need to be exhausted for energy generation to cease. If glycogen is a limiting factor, as found with head-only stunning, pH drops too rapidly and affects water-holding capacity and color. Hemorrhage scores were higher with electrical stunning than with other stunning methods. Gas stunning affected color and, to a lesser extent, water-holding capacity. Captive needle stunning scored between gas and electrical stunning on most measurements.
屠宰前使家禽昏迷的一般方法是将鸡头浸入带电的水浴中。这种方法会导致胴体和肉质出现缺陷。主要问题是出血和尸僵开始延迟，这增加了早期去骨时冷收缩的风险。在两项实验中，本研究考察了胸肌宰后早期代谢及其对最终肉质的影响。第一个实验描述了禁食5小时对肝脏和胸肌糖原可用性的影响，未处理肌肉中水浴和仅头部电击致昏对pH值和代谢物水平长达6小时的影响，以及对肉质的影响。第二个实验比较了水浴和仅头部电击致昏、二氧化碳/氧气/氮气和氩气/二氧化碳气体以及俘获针致昏后的相同测量结果。未经处理6小时后或在水浴和二氧化碳/氧气/氮气致昏后的常规条件下4小时后，代谢降解停止。使用其他致昏方法时，这种情况发生得更快，很大程度上取决于肌肉活动。肌肉糖原耗尽并不一定是能量产生停止的必要条件。如果糖原是一个限制因素，如仅头部致昏时发现的那样，pH值下降过快，会影响持水能力和颜色。电击致昏的出血评分高于其他致昏方法。气体致昏会影响颜色，并在较小程度上影响持水能力。在大多数测量中，俘获针致昏的评分介于气体致昏和电击致昏之间。
