Smulders F J, Eikelenboom G, van Logtestijn J G
Department of the Science of Food of Animal Origin, Faculty of Veterinary Medicine, The University of Utrecht, Utrecht, The Netherlands.
Meat Sci. 1986;16(2):91-101. doi: 10.1016/0309-1740(86)90068-9.
Meat bulls were randomly assigned to five treatment groups-intermittent electrical stimulation at 300 V (ES) at 5 min and 35 min post mortem (intact carcasses), 35 min post mortem (split carcasses) and non-stimulated controls (NS) (intact and split carcasses). Stimulated carcasses in all groups showed a significantly more rapid pH fall during the first 8h post mortem in adductor (AD), longissimus dorsi (LD) and triceps brachii (TB) muscles. Cooling rates were relatively slow. Samples were removed from the carcass at 24h post mortem. After vacuum storage at 3°C for 6 days stimulated muscles showed lower drip (LD and TB) and heating loss (TB), lower shear force values (AD, LD and TB) and higher taste panel scores (AD, LD and TB) compared with NS controls. No significant differences in tenderness were observed between the three ES groups. Sarcomere length assessment showed more contraction in NS carcasses, particularly in the superficially located LD and TB. These results suggest that cold shortening may occur in some muscles under cooling conditions so far considered safe in this respect. Since higher drip losses coincided with lower sarcomere lengths in these (NS) muscles, it is suggested that, under these conditions, ES may mask the increased drip losses which are possibly the result of muscle contraction. Furthermore, ES prevents the occurrence of cold shortening and, in addition, may exert some 'extra tenderising effect', which is not related to splitting of the carcass nor restricted merely to the LD muscle.
肉用公牛被随机分配到五个处理组，即宰后5分钟和35分钟时以300伏进行间歇性电刺激（完整胴体）、宰后35分钟时进行电刺激（二分胴体）以及非刺激对照组（完整和二分胴体）。所有组中接受刺激的胴体在内收肌（AD）、背最长肌（LD）和肱三头肌（TB）肌肉宰后最初8小时内pH值下降明显更快。冷却速度相对较慢。宰后24小时从胴体上取样。与非刺激对照组相比，在3℃真空储存6天后，接受刺激的肌肉滴水损失（LD和TB）和热损失（TB）更低，剪切力值（AD、LD和TB）更低，味觉评分（AD、LD和TB）更高。三个电刺激组之间在嫩度上未观察到显著差异。肌节长度评估显示，非刺激组胴体的收缩更明显，尤其是表层的LD和TB。这些结果表明，在迄今认为在这方面安全的冷却条件下，某些肌肉可能会发生冷收缩。由于在这些（非刺激）肌肉中较高的滴水损失与较短的肌节长度同时出现，因此表明在这些条件下，电刺激可能掩盖了可能由肌肉收缩导致的增加的滴水损失。此外，电刺激可防止冷收缩的发生，而且可能会产生一些“额外的嫩化效果”，这与胴体二分无关，也不仅限于LD肌肉。
