油茶籽油对鱼糜凝胶特性及凝胶结构的影响

为探讨脂质对鱼糜蛋白凝胶功能特性的影响及其机理,研究不同油茶籽油添加量对鱼糜凝胶特性、水分分布、脂质及蛋白质结构等的影响。结果表明:随着油茶籽油添加量的增加,鱼糜凝胶强度、乳化稳定性和持水性显著增加(P0.05),当油茶籽油添加量增加到8%时各指标基本稳定,此时鱼糜凝胶强度为225.1 g·cm,游离出来的液体质量分数为2.60%。拉曼光谱分析发现,油茶籽油的添加改变了鱼糜凝胶体系中脂质和蛋白质的化学结构,主要表现为C—H谱带峰宽的增加、O—H谱带相对强度的下降,以及鱼糜蛋白中β-折叠、β-转角和无规卷曲结构相对含量的增加和α-螺旋结构相对含量的降低。同时,随着油脂质量分数的增加,水分以更加细小的状态分布在鱼糜凝胶体系之中。以上结果进一步揭示了油茶籽油的添加可增加鱼糜凝胶强度、乳化稳定性和持水性的内在原因。

Effect of Camellia Tea Oil on Properties and Structure of Surimi Gels

The objective of this study was to investigate the effect of camellia tea oil on gel strength, water distribution, lipid and protein structure of surimi gels. The results showed that added oil resulted in a significant increase in gel strength, emulsion stability and water-holding capacity of surimi gels (P < 0.05), and when the oil concentration was increased to 8%, these parameters basically kept stable. Under this condition, the gel strength was 225.1 g·cm and the percentage of total expressible fluid (TEF) was 2.60%. Raman spectroscopy analysis revealed that the addition of camellia tea oil changed the structure of lipid and protein in surimi gels, as indicted mainly by the increased width of C?H band, the decreased intensity of O?H band and the increased contents of β-sheet, β-turn and random coil accompanied by the decreased content of α-helix in surimi protein. Meanwhile, with increasing added oil, the water was distributed in a much smaller state in surimi. These findings may further explain the mechanism for the effect of exogenous oil on gel strength, emulsion stability and water-holding capacity of surimi gels.