为探究Ca2+离子对低酯果胶/海藻酸钠复合凝胶体系的影响，向总质量浓度为1 g/100 mL的复合凝胶中，分别加入不同浓度的CaCl2溶液，研究复合凝胶的流变学特性以及微观结构的变化。结果表明，复合凝胶体系的剪切应力随着Ca2+的加入有所下降，在9 μmol/mL达到最小，继续添加Ca2+又有所回升。复合凝胶体系的黏度则随着Ca2+的加入持续升高，且复合凝胶表现出典型的假塑性流体的特征，加入Ca2+后复合凝胶体系的流体指数n均有所下降，稠度系数K在复合凝胶Ca2+添加浓度达到最小为9 μmol/mL。复合凝胶动态黏弹性会随着Ca2+的加入量增加，出现明显变化，凝胶体系的储能模量随着Ca2+的加入持续升高，损耗角正切逐渐减小，但Ca2+浓度大于9 μmol/mL时损耗角正切有所回升。微观结构观察表明，Ca2+的加入有助于凝胶多孔的形成，在Ca2+的加入量达到9 μmol/mL时凝胶的网孔最多且最为致密，继续加入Ca2+后凝胶的孔洞数量减少且凝胶网络不再明显，其扫描电镜观察图更类似未添加Ca2+的复合凝胶电镜观察图。

In order to investigate the effect of calcium on low methoxyl pectin/sodium alginate mixed gel system, different concentration of CaCl2 was added into 1 g/100mL of mixed gel system to study the changes in rheological properties and microstructure. The results showed that the shear stress of the mixed gel system decreased with the addition of Ca2+ and reached its minimum at 9 μmol/mL, but shear stress increased after continuing adding Ca2+. The viscosity of the mixed gel system increased with Ca2+, and the mixed gel exhibited the characteristics of the typical pseudoplastic fluid. After adding Ca2+, the fluid index n of the mixed gel system decreased, and the consistency coefficient K was at the highest at the concentration of 9 μmol/mL. The dynamic viscoelasticity of the composite gel changed obviously with the increasing of Ca2+. The storage modulus of the gel system increased with the addition of Ca2+, but the loss tangent decreased gradually. The loss tangent rose again when the calcium ion concentration was more than 9 μmol/mL. Microstructure observation showed that Ca2+ contributeed to the formation of gel pores and when the amount of Ca2+ was at 9 μmol/mL, the mixed gel system had the largest and most dense pores. The number of pores in the gel decreased and the gel network was no longer strong after continuing adding Ca2+, at which point, the scanning electron microscopy was more similar to the mixed gel system without Ca2+.