超声辅助解冻对秘鲁鱿鱼胴体蛋白氧化与品质的影响

Effect of Ultrasound-Assisted Thawing on Protein Oxidation and Quality of Frozen Jumbo Squid(Dosidicus gigas)

本研究旨在探讨超声辅助解冻过程中蛋白质氧化、肌肉结构变化与秘鲁鱿鱼胴体品质的关系。采用不同梯度的超声功率(100、300、500 W),在不同温度(5、10℃)下对秘鲁鱿鱼胴体进行超声辅助解冻处理。经U5-5(5℃、500 W)超声解冻处理的鱿鱼解冻和蒸煮质量损失最少,低场核磁共振实验结果也显示,U5-5超声解冻处理可以降低汁液流失。7种不同解冻方式的鱿鱼羰基含量、总巯基含量、二聚酪氨酸含量和表面疏水性差异显著(P<0.05)。U5-3(5℃、300 W)、U5-5超声解冻处理对肌原纤维蛋白羰基含量影响小,U5-3超声解冻组的总巯基含量最高,二聚酪氨酸含量最低,冷藏解冻和U5-1(5℃、100 W)超声解冻组蛋白质表面疏水基团暴露最少。拉曼光谱分析结果表明,超声辅助解冻可以延缓α-螺旋向β-折叠、β-转角和无规卷曲结构转化。综上,5℃超声辅助解冻(U5-3、U5-5)可以改善秘鲁鱿鱼产品品质,延缓蛋白氧化。

The objective of the present study was to explore the relationship of protein oxidation,muscle structural changes and jumbo squid mantle quality during ultrasound-assisted thawing.Frozen jumbo squid mantles were thawed by ultrasonic treatment using different power gradients(100,300,and 500 W)at different temperatures(5 and 10℃).The U5-5 treatment(5℃,500 W)caused the smallest thawing and cooking loss.Low-field nuclear magnetic resonance(LF-NMR)suggested that U5-5 could reduce juice loss.The seven different thawing methods showed significant differences in carbonyl content,total sulfhydryl content,dityrosine content and surface hydrophobicity(P<0.05).U5-3(5℃,300 W)and U5-5 had little effect on the carbonyl content of myofibrillar protein.U5-3 caused the highest total sulfhydryl content and the smallest dityrosine content,while refrigerator thawing and U5-1(5℃,100 W)caused the least exposure of hydrophobic groups on the protein surface.Raman spectroscopy showed that ultrasonic-assisted thawing could retard the conversion ofα-helices toβ-sheets,β-turns and random coils.These results demonstrate that ultrasonic-assisted thawing at 5℃(U5-3 and U5-5)can improve product quality and defer protein oxidation.