研究反复冻融对秘鲁鱿鱼肌原纤维蛋白及肌肉品质的影响，为水产品保鲜提供理论依据。将鱿鱼肌肉分别进行0、1、3、5、7次冻融处理，测定蛋白羰基、总巯基、表面疏水性、蛋白的聚集情况及蛋白浊度、乳化活性、乳化稳定性等，并结合感官评价对肌肉品质如解冻损失、蒸煮损失、色泽、嫩度、质构特性及肌肉脂肪氧化程度等进行分析。结果发现经过冻融处理后，蛋白羰基含量和表面疏水性增加，总巯基含量下降，蛋白出现一定程度的聚集，肌原纤维蛋白的浊度增加，乳化活性和乳化稳定性降低。随着冻融次数的增加，鱿鱼肌肉脂肪氧化程度、解冻损失、蒸煮损失、b*等显著增加（p<0.05），而L*、a*、W、嫩度、弹性和硬度等下降，同时感官评价结果和仪器分析结果保持一致。因此，反复冻融促进蛋白和脂肪发生氧化，导致鱿鱼肌肉品质下降。

Effects of different freeze-thaw cycles on proteins and muscle quality of Dosidicus gigas were studied to provide a theoretical basis for the preservation of aquatic products. Protein carbonyl content, total sulfhydryl content, surface hydrophobicity, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) pattern, turbidity, emulsifying activity index (EAI) and emulsifying stability index (ESI) of the treated samples were measured after 0, 1, 3 ,5 and 7 freeze-thaw cycles. And the thawing loss, cooking loss, color, tenderness, texture and thiobarbituric acid reactive substances (TBARS) of squid muscle were analyzed combined with organoleptic evaluation. With increasing the number of freeze-thaw cycles, protein carbonyl content and surface hydrophobicity increased but total sulfhydryl content of myofibrillar proteins exhibited the opposite trend. Aggregation of proteins was found during the process and EAI and ESI dropped markedly. Moreover, TBARS, thawing loss, cooking loss and b* significantly increased (p<0.05), while L*, a*, whiteness, tenderness, springiness and hardness decreased. Results from organoleptic evaluation were in consistence with the instrumental ones. In summary, repeated freeze-thaw cycles promotes oxidation of protein and lipid and has a detrimental effect on the qualities of squid muscle.

国家科技支撑计划课题（2012BAD38B09）