pH值对海藻酸丙二醇酯溶液流变特性的影响

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-G2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。

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

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 rheological 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 carried 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.