光谱学与光谱分析, 2010, 30 (8): 2196, 网络出版: 2011-01-26
应用动态光散射和透射电镜研究热力学不相容条件下果胶与乳清蛋白混合体系的微观结构
Study of Microstructure of Pectin and Whey Protein Isolate Mixtures under Incompatible Conditions Using Dynamic Light Scattering and Transmission Electron Microscopy
摘要
应用动态光散射、 透射电镜和粘度-剪切模型3种方法互相配合, 研究了果胶与乳清分离蛋白的混合体系在热力学不相容条件下的微观结构。 在90 ℃及pH 7.4条件下, 向5%蛋白浓度的乳清蛋白溶液中加入带有负电的果胶分子, 可导致热变性乳清蛋白分子之间发生损耗聚集, 并引发混合体系内的相分离现象。 确切地说, 当果胶与乳清蛋白的混合重量比小于0.08时, 溶液内可观察到粒径小于300 nm的聚集颗粒, 体系呈现牛顿流体特征; 而当混合重量比大于0.08时, 体系粘度上升, 切稀特征逐渐明显, 聚集集团粒径接近700 nm。
Abstract
The microstructure of the pectin/whey protein isolate mixtures under incompatible conditions was investigated using dynamic light scattering spectroscopy, transmission electron microscopy and shear-viscosity model. Under the condition of 90 ℃ and pH 7.4, the presence of negatively charged pectin could induce depletion aggregation in a 5% protein solution, and promote phase separation; precisely, when the mass ratio of pectin/whey protein isolate was lower than 0.08, the hydrodynamic size of the aggregates was less than 300 nm, and the system showed Newtonian properties; when the mass ratio was higher than 0.08, the viscosity of the solution increased rapidly, the shear thinning properties became obvious and the size of the aggregates was close to 700 nm.
冷小京, 柴智, 任发政, 张录达, Turgeon S L. 应用动态光散射和透射电镜研究热力学不相容条件下果胶与乳清蛋白混合体系的微观结构[J]. 光谱学与光谱分析, 2010, 30(8): 2196. LENG Xiao-jing, CHAI Zhi, REN Fa-zheng, ZHANG Lu-da, Turgeon S L. Study of Microstructure of Pectin and Whey Protein Isolate Mixtures under Incompatible Conditions Using Dynamic Light Scattering and Transmission Electron Microscopy[J]. Spectroscopy and Spectral Analysis, 2010, 30(8): 2196.