不同超声辅助解冻方式对海鲈鱼品质的影响

将五种解冻处理的海鲈鱼(超声微波解冻、超声远红外解冻、超声欧姆解冻、超声真空解冻和超声解冻)与新鲜鱼肉进行比较,研究了不同解冻方式对海鲈鱼品质的影响。本文主要分析了解冻后鱼肉的持水性、新鲜度、脂肪氧化程度、蛋白质热稳定性、凝胶特性、水分分布和微观结构的变化。结果显示,不同处理的解冻损失率和蒸煮损失率差异显著(P<0.05),超声微波解冻鱼肉的解冻损失率和蒸煮损失率最低,分别为1.52%和13.13%。低场核磁的结果显示超声微波解冻的样品中,细胞内水分向游离水迁移较少,说明超声微波解冻的鱼肉持水性较高。所有解冻样品的pH均与新鲜样品没有显著性差异(P>0.05),TVB-N值均低于15 mg/100 g,保持了较高的新鲜度。但超声远红外解冻、超声欧姆解冻、超声真空解冻和超声解冻的鱼肉TBARS值显著升高(P<0.05),脂肪氧化程度较高。超声微波解冻和超声远红外解冻的海鲈鱼具有较高的热稳定性和粘弹性,并且拥有更紧密光滑的微观结构。超声真空解冻的肌原纤维束发生轻微卷曲,超声欧姆解冻和超声解冻的纤维表面粗糙、结构疏松。其中,超声微波解冻是最优的解冻方式。

Effects of Different Ultrasound-assisted Thawing Methods on the Quality of the Sea Bass

Five thawing treatments of sea bass(ultrasonic microwave thawing,ultrasonic far-infrared thawing,ultrasonic ohmic thawing,ultrasonic vacuum thawing,and ultrasound thawing)were compared with fresh fish,and the effects of different thawing methods on the quality of sea bass were studied. The changes of water holding capacity,freshness,lipid oxidation degree,protein thermal stability,gel properties,water distribution and microstructure of thawed fish were analyzed mainly in this article. The results showed that the thawing loss rate and cooking loss rate were significantly different in different treatments(P<0.05). The thawing loss rate and cooking loss rate of fish by ultrasonic microwave thawing were the lowest,1.52% and 13.13% respectively. The results of LF-NMR showed that in the samples thawed by ultrasonic microwave,the water migration from intracellular water to free water was less,indicating that the water holding capacity of the fish thawed by ultrasonic microwave was stronger. The pH values of all thawed samples were not significantly different from fresh samples(P>0.05)and the TVB-N values were all below 15 mg/100 g,maintaining a high degree of freshness. However,The TBARS values of the fish thawed by ultrasonic far-infrared,ultrasonic ohmic,ultrasonic vacuum and ultrasound were significantly increased(P<0.05),indicating a higher degree of lipid oxidation. The sea bass of ultrasonic microwave thawing and ultrasonic far-infrared thawing had higher thermal stability,viscoelasticity,and the microstructures were more dense and smooth. But the myofibril bundles were slightly crimped by ultrasonic vacuum thawing,and the fibers by ultrasonic ohmic thawing and ultrasonic thawing had rough surface and loose structure.