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本文研究了五种壁材分子结构及其流变学特性。以喷雾干燥制备微胶囊的五种常用壁材变性淀粉、阿拉伯胶、明胶、大豆分离蛋白和羧甲基纤维素为研究对象,采用凝胶渗透色谱法(GPC)测定壁材的分子量分布;傅里叶变换红外光谱法(FT-IR)分析不同壁材的特征基团和蛋白类壁材的二级结构;旋转流变仪研究壁材的表观黏度、动态模量和蠕变柔量。研究结果表明:五种壁材溶液均呈现剪切稀化现象,随着温度的上升壁材溶液的表观黏度逐渐下降;壁材的弹性模量G’和黏性模量G’均随着振荡频率的增大而增大;相同时间下,壁材的蠕变柔量J(t)大小为:变性淀粉>阿拉伯胶>明胶>羧甲基纤维素>大豆分离蛋白;壁材分子量越大,表观黏度就越大;同一数量级分子量的壁材,分子量分布越宽,非牛顿“剪切稀化”现象越明显;分子结构越刚性,极性越大,表观黏度也越大。
In this paper, five kinds of wall materials molecular structure and rheological properties. The five commonly used wall materials, such as modified starch, gum arabic, gelatin, soybean protein isolate and carboxymethyl cellulose, were prepared by spray drying. The molecular weight distribution of the wall material was determined by gel permeation chromatography (GPC) The Fourier transform infrared spectroscopy (FT-IR) was used to analyze the secondary structure of the characteristic groups and protein wall materials of different wall materials. The rotational viscosities were used to study the apparent viscosity, dynamic modulus and creep compliance of the wall materials. The results show that all the five kinds of wall materials exhibit shear thinning phenomenon, and the apparent viscosity of the wall material gradually decreases with the increase of temperature. Both the elastic modulus G ’and the viscous modulus G’ The amplitude of creep of the wall material J (t) at the same time: modified starch> gum arabic> gelatin> carboxymethylcellulose> soy protein isolate; the greater the molecular weight of the wall material , The apparent viscosity is greater; the molecular weight distribution of the same order of magnitude of the wall material, the wider the non-Newton “shear thinning ” phenomenon more obvious; the more rigid the molecular structure, the greater the polarity, the greater the apparent viscosity .