海藻糖对冻藏过程中鳙肌原纤维蛋白冷冻变性的影响

Effects of trehalose on denaturation of bighead carp (Aristichthys nobilis) myofibrillar protein during frozen storage

从鳙(Aristichthys nobilis)肌肉中提取肌原纤维蛋白,在蛋白溶液中加入10%(W/V)蔗糖、山梨醇混合物(质量比1∶1)或10%(W/V)海藻糖。蛋白溶液在-18℃下冻藏30 d,测定冻藏过程中肌原纤维蛋白盐溶性、Ca2+-ATPase活性、活性巯基含量、总巯基含量、表面疏水性变化和冻藏结束时的SDS-PAGE。测定结果表明,蔗糖、山梨醇混合物和海藻糖都抑制了冻藏过程中肌原纤维蛋白盐溶性、Ca2+-ATPase活性、巯基含量的降低和表面疏水性的升高,延缓了鳙肌原纤维蛋白的冷冻变性。海藻糖比蔗糖、山梨醇混合物有更好的抗冷冻变性效果。[中国水产科学,2006,13(4):637-641]

During the frozen-storage, fish muscle undergoes some deterioration in edible qualities and functional properties for processing. The deterioration of muscle is mainly attributed to the frozen denaturation of myofibirillar protein. Trehalose is a non-reducing disaccharide with low caloric value and low sweetness. It is very stable in properties and can protect biological cells under adverse circumstances. Trehalose has protective effect against thermal inactivation of enzymes. Hence, the suppressive effect of trehalose on protein frozen denaturation is expected. In this study, the effect of trehalose on denaturation of bighead carp （Aristichthys nobilis ） myofibrillar protein during frozen storage was studied. Myofibrillar protein was drawn from bighead carp muscle. Protein solution containing 10% （W/V） blend of sucrose and sorbitol （1： 1） or 10% （W/V） trehalose was stored at -18℃ for up to 30 days. The change of myofibirllar protein salt solubility, Ca^2＋-ATPase activity, active sulfhydyl content, total sulfhydyl content, surface hydrophobicity and SDS-PAGE was mensurated during frozen storage. During frozen storage, myofibirllar protein showed a time dependent biphasic denaturation pattern. Addition of Trehalose or mixture of sucrose and sorbitiol maintained protein salt solubility, Ca^2＋ -ATPase activity, active sulfhydyl content, total sulfhydyl content and surface hydrophobicity. After 30 days of frozen storage, the protein salt solubility and ATPase activity sharply decreased to 50% and 35%, while the value of protein with trehalose was 85 % and 82 %. Trehalose exhibited greater protective effect on protein frozen denaturation than the mixture of sucrose and sorbitiol. Therefore trehalose appeared to be the promising alternative cryoprotectant owing to its low sweetness and low caloric value. [Journal of Fishery Sciences of China, 2006,13 （4） ： 637 - 641]