金枪鱼肌原纤维蛋白热凝及流变特性的研究
Heating-induced gel and rheological properties of tuna myofibrillar protein
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摘要: 鱼肉的组织学特性和肌原纤维蛋白的凝胶学特性有很大的相关性。深入探讨金枪鱼肉肌原纤维凝胶体系的凝胶机理,有利于开发保证质量的金枪鱼肉制品。本研究通过小振幅及大振幅振荡剪切流变学方法,探讨NaCl浓度(0.3~0.6mol/L)对金枪鱼肌原纤维蛋白热凝胶特性及流变特性的影响。结果表明,热诱导凝胶过程中,在47℃之前,弹性模量(G’)随NaCl浓度的增加而增大,在47℃之后总体趋势发生改变,G’在NaCl浓度为0.4mol/L达到最大值。NaCl浓度在肌原纤维蛋白凝胶形成过程中对流变的影响最大。对数模型能很好地关联线性粘弹性区间的应变同G’的数量关系。大振幅振荡测试(LAOS)表明,随着浓度的增加,网络结构更紧密,剪切一周期所消耗能量越大,在较大的应变下能够更稳定地保持线性粘弹性。Abstract: The gelation characteristics of myofibrillar proteins are indicative of fish product texture.Gaining an additional insight of the gelation mechanism of tuna meat gel system was beneficial for the development of processed tuna products as well as maintaining quality in meat products.The effect of NaCl concentration (0.3 ~0.6mol/L) , on tuna myofibrillar protein gelation and rheological properties were studied using dynamic oscillatory rheometer of both small-amplitude oscillatory shear (SAOS) and large-amplitude oscillatory shear (LAOS) .The results showed that during the gel heating-induced process, the G ' of myofibrillar protein increased with the increase of NaCl concentration before 47℃.But this general trend changed after 47℃, G' reached a maximum value at NaCl concentration 0.4mol/L.The influence of NaCl was stronger during the period of gel formation.The relationship between its storage modulus and strain within could be described by the logarithmic model.The LAOS tests showed that the higher NaCl concentration would bring closer network structure and larger energy dissipated (Ed) during a sinusoidal stress cycle.The higher NaCl concentration would be able to hold linear viscoelasticity steadily.