淮山药黏液稳定性与黏弹响应的关系

Relationship between the Stability and Viscoelastic Response of Yam Mucilage

研究了淮山药黏液稳定性与黏弹响应的关系,发现在测试频率范围内,储能模量(G)始终大于损耗模量(G″),且均随频率变化不大,呈现出较强的网络结构特征,黏液性质对频率不敏感。黏液的表观黏度(a)与剪切速率(■)的关系可用Carreau模型较好地拟合,增大,黏液发生剪切变稀现象,表明黏液性质对剪切速率的变化较敏感;黏液的增比黏度(ηsp)与浓度(c)的关系为ηsp∝c3.01±0.12,黏液处于亚浓缠结区域。此外,盐度对黏液的黏弹响应影响较大,盐度增加,蛋白质分子间的静电排斥作用被屏蔽,分子间缠结增强,黏液的储能模量、损耗模量以及复数黏度(η*)逐渐上升,对黏液稳定性有一定影响。

Relationship between mucilage stability viscoelastic response of yam mucilage under different conditions was investigated.The dynamic storage modulus（G） and dynamic loss modulus（G″） of the mucilage increase slowly with increasing angular frequency（ω）,which shows strong network structure characteristics and good stability.G G suggests that the yam mucilage exhibits more elasticity than viscidity.The relationship between apparent viscosity（ηa） of yam mucilage and shear rate（γ） can be well described by the Carreau model.Moreover,the relationship between specific viscosity（ηsp） and concentration（c） follows ηsp∝c3.01±0.12,which suggests that it is in the semidilute entangled regime.G,G and complex viscosity（η＊） of mucilage increase with increasing salt concentration,which may be attributed to the electrostatic repulsion between protein molecules is screened and it favors the entanglement of chains.The breakdown of Cox-Merz rule reveals that the long-range interaction exists among components in yam mucilage.