pH值对海藻酸丙二醇酯溶液流变特性的影响

Effect of pH on the Rheological Properties of Propylene Glycol Alginate Aqueous Solution

作为一种增稠剂,海藻酸丙二醇酯广泛应用于乳制品或乳饮料中。采用AR-G 2流变仪,通过稳态流动、应变扫描、频率扫描、动态黏弹性温度扫描及动态黏度温度扫描等实验研究pH值对海藻酸丙二醇酯溶液流变特性的影响。结果表明:pH值的增加使海藻酸丙二醇酯溶液的黏度降低,同时使其黏弹性与复合黏度降低,损耗正切增加。另外,pH值低于7时,海藻酸丙二醇酯溶液的剪切稀化程度减弱,pH值高于7时,溶液的剪切稀化程度增强。同时,pH值影响海藻酸丙二醇酯溶液的黏度及黏弹性的温度效应。

Propylene glycol alginate is widely used in dairy products or milk-based beverages as a thickener. The aim of the work was to study the influence of pH on the rbeological properties of propylene glycol alginate solution. For this purpose, steady-state flow sweep, strain sweep, frequency sweep, dynamic viscoelasticity temperature sweep and dynamic viscosity temperature sweep experiments were carded out with an AR-G 2 rheometer. The experimental results showed that the viscosity, viscoelasticity, and complex viscosity of propylene glycol alginate solution decreased as pH increased, while the loss tangent increased. Meanwhile, at pH below 7 the degree of shear thinning decreased while it increased at pH above 7. In addition, pH influenced the effect of temperature on the viscosity and viscoelasticity of propylene glycol alginate solution.