冷冻-解冻循环对鲤鱼肉物理化学特性的影响

研究不同冷冻-解冻循环次数(0、1、3、5次)对鲤鱼脊背肉pH值、失水率、蒸煮损失、剪切力、肌肉颜色、硫代巴比妥酸值(TBARS)、羰基含量和电泳图谱的影响，从而确定冻融次数对鱼肉物理化学特性的影响。结果表明：随着冷冻-解冻循环次数的增加，鱼肉pH值呈现出先上升后下降的趋势；失水率和蒸煮损失不断增加，到第5次循环时分别增加了8.77%和20.28%，且差异显著(P＜0.05)；剪切力经1次冷冻-解冻循环后降低56.3%，随后缓慢下降；TBARS值、羰基含量L* 和b*值不断增加，而a*值逐渐降低；鱼肉肌原纤维蛋白所有条带都不同程度的变淡，甚至消失，蛋白降解而变性。且脂肪氧化和颜色变化及蛋白氧化有一定的相关性。因此，反复冷冻-解冻使蛋白质变性，严重影响了鲤鱼鱼肉品质特性。

Effect of Number of Freeze-thaw Cycles on Physico-chemical Characteristics of Carp Muscle

The pH,water loss rate,cook loss,shear force,color parameters,thiobarbituric acid reactive substances(TBARS),carnonyl content and sodium dodecyl sulphate polyacrylamide gel electrophoresis(SDS-PAGE) pattern of carp back muscles were measured after different freeze-thaw cycles(0,1,3 and 5) with the aim of determining the effect of number of freeze-thaw cycles on the physicochemical characteristics of carp muscle.Results indicated that pH value showed a trend to first increase and then decrease as the number ...