den Hertog-Meischke M J, Klont R E, Smulders F J, van Logtestijn J G
Department of the Science of Food of Animal Origin, Faculty of Veterinary Medicine, Utrecht University, PO Box 80175, 3508 TD Utrecht, The Netherlands.
Meat Sci. 1997 Nov;47(3-4):323-9. doi: 10.1016/s0309-1740(97)00064-8.
In this study the effect of the rate of post mortem pH fall on the water-holding capacity of meat from moderately chilled veal carcasses was investigated. Also the relationship between muscle protein denaturation and drip loss of veal was examined. Three groups of 10 Friesian Holstein male veal calves each were selected on the basis of their pH in M. longissimus thoracis et lumborum (LTL) at 3 hr post mortem (pH(3)): (1) fast pH-fall, pH(3) < 6.2; (2) intermediate pH-fall, 6.5 < pH(3) < 6.6; (3) slow pH-fall, pH(3) > 6.7. After 48 hr of chilling the LTL was excised from the carcass and sampled for determination of drip loss, filter paper wetness, sarcomere length, protein solubility and transmission value. Differences in pH(3) were not associated with differences in drip loss, filter paper wetness or differences in protein denaturation. It is suggested that at the relatively high veal carcass chilling rate the effect of rate of pH-fall on protein denaturation and thus on drip loss is negligible. Drip loss of veal was highly correlated with both solubility of sarcoplasmic (r = -0.67; p < 0.001) and total muscle protein (r = -0.54; p < 0.01) and with transmission values (r = 0.66; p < 0.001). These results indicate that protein denaturation measurements may be a good predictor for drip loss of veal.
本研究调查了宰后pH值下降速率对中度冷却小牛肉胴体肉保水能力的影响。同时还研究了小牛肉肌肉蛋白质变性与滴水损失之间的关系。根据宰后3小时胸腰段最长肌（LTL）的pH值，选择三组，每组10头弗里生-荷斯坦雄性犊牛：（1）pH值快速下降组，pH（3）<6.2；（2）pH值中等下降组，6.5<pH（3）<6.6；（3）pH值缓慢下降组，pH（3）>6.7。冷却48小时后，从胴体上切下LTL并取样，测定滴水损失、滤纸湿度、肌节长度、蛋白质溶解度和透光率值。pH（3）的差异与滴水损失、滤纸湿度或蛋白质变性的差异无关。研究表明，在相对较高的小牛肉胴体冷却速率下，pH值下降速率对蛋白质变性进而对滴水损失的影响可忽略不计。小牛肉的滴水损失与肌浆蛋白溶解度（r = -0.67；p < 0.001）和总肌肉蛋白溶解度（r = -0.54；p < 0.01）以及透光率值（r = 0.66；p < 0.001）均高度相关。这些结果表明，蛋白质变性测量可能是预测小牛肉滴水损失的良好指标。
