冻结速率和冻藏温度对文蛤蛋白质冷冻变性的影响

Effects of Freezing Rate and Frozen Stored Temperature on Freeze Denaturation of the Meretrix linnaeus Protein

利用IMP热电偶测温系统，对文蛤分别在-18℃和-30℃冻结温度下的冻结过程进行了测量，对-18℃和-30℃下3种贮藏形态的贝肉冻结样品和冻藏样品肌原纤维蛋白的Ca^(2+)-ATPase活性、Mg^(2+)-ATPase活性、盐溶性蛋白溶解度及添加抗冻剂后防止其冷冻变性的影响进行了研究。结果发现，冻结对贝肉蛋白质变性影响不大，冻藏使蛋白质发生显著的变性，温度低的变性小；在贮藏贝肉的3种形态中，无完整细胞形态的贝糜的变性幅度最大，碎贝肉次之，贝肌肉形态的保持得较好；添加抗冻剂能有效防止贝肉蛋白质冷冻变性，尤其能使贝糜形态贝肉蛋白质的稳定性大大提高。

Utilize the IMP system of temperature measurement on the freezing course of the Meretrix Linnaeus under - 18℃ and - 30℃ to study effect of the protein denaturizing with cryoprotectants or the salt-solubility and activity of Ca^2-ATPase and Mg^2＋ -ATPase of myofibrillar protein. The results showed that the freezing rate have little effect on denaturizing of the Meretrix Linnaeus. However, the frozen storage temperature had a big influence, the lower the temperautre, the less the extent of freeze denaturizing; among the three forms of the Meretrix Linnaeus, minced shellfish or surimi structure destroyed more severly than intact muscle tissue. It was also observed that denaturizing of myofibrillar protein in fish muscle could be efficiently reduced by adding cryoprotectants, especially in surimi.