海藻酸钠和刺槐豆胶对小麦淀粉流变学及质构性质的影响

Effects of Sodium Alginate and Locust Bean Gum on Rheological and Texture Properties of Wheat Starch

为进一步改善小麦淀粉凝胶性质,通过动态流变学、静态流变学、光学微流变等方法探讨海藻酸钠(AG)和刺槐豆胶(LBG)两种亲水胶体的复配比对小麦淀粉黏弹性和凝胶质构的影响。结果表明,添加不同配比的AG和LBG均能提高小麦淀粉凝胶的储能模量、损耗模量和稠度系数,降低损耗因子,AG与LBG复配物具有良好的增稠效果。小麦淀粉-亲水胶体复配体系的黏度随剪切速率升高而降低,表现出剪切变稀的假塑性行为,符合幂定律模型。光学微流变结果证实,AG和LBG的加入提高了小麦淀粉凝胶的弹性指数和黏性指数,降低固液平衡指数。当AG与LBG质量比为1∶1时,AG和LBG之间存在协同作用,小麦淀粉凝胶更为致密、弹性更强,表现出最优的黏弹性。

To further improve the gel properties of wheat starch,the effects of sodium alginate(AG)to locust bean gum(LBG)ratio on the viscoelasticity and gel texture of wheat starch were investigated by dynamic rheology,steady rheology and diffusing wave spectroscopy.The results showed that storage modulus,loss modulus and consistency coefficient of wheat starch gel were increased,while loss factor was decreased with the addition of AG and LBG with different ratio.The viscosity of wheat starch-gum blends decreased with the increase of shear rate,showing pseudoplastic behavior of shear thinning.This was in line with the power law model.The results of diffusing wave spectroscopy confirmed that elastic index and viscosity index of wheat starch gel were increased,while solid-liquid index was decreased with the addition of AG and LBG.When the mass ratio of AG to LBG was 1∶1,there was a synergistic effect between AG and LBG that could cause wheat starch forming dense and elastic gels with optimal viscoelasticity.