鲤在-20℃冻藏过程中的质地变化

Texture changes of common carp (cyprinus carpio) stored at-20℃

镀冰衣和用低密度塑料袋包装的鲜鲤经七个月的冻藏(-20℃)仍被感官检验所能接受,而未经包装的鲤体表却出现了白霜。鲤肌肉蛋白质在冻藏过程中发生了变性:盐溶性蛋白质、蛋白质保水性下降,ATP酶相对活力降低,鱼肉质地变性。蛋白质的物理和化学指标变化与鱼肉质地的感官变化具明显相关性。游离脂肪酸的增加和PH值的变化在一定程度上也影响蛋白质的变性。

Frozen storage of fresh water fish, with respect to extending their shelf life, has become very important in recent years, since the frozen fresh water fish are accepted by consumers rather than cured fresh water fish, carp were still acceptable to consumers after 7 month's storage at - 20℃ when glazed and low density polyethylene wrapped but otherwise acquired a surface whiteness after 140 day's storage. The texture changes indicated by sensory analysis were related to texture measurements made on the Steven's LFRA Texture Analyser and originated from protein denaturation as indicated by changes in % of salt-soluble proteins, water holding capacity, ATPase relative activities. The formation of free fatty acids and the changes of PH may also affect protein denaturation.