大豆分离蛋白与壳聚糖复合材料的制备  

Preparation of Composite Based on Soybean Protein Isolates and Chitosan

作　　者：赵伟刚[1] 鹿振武 逯盛芳 何乃普[1] 

机构地区：[1]兰州交通大学化学与生物工程学院,兰州730070

出　　处：《应用化学》2015年第3期327-334,共8页Chinese Journal of Applied Chemistry

基　　金：国家自然科学基金(21164003);甘肃省自然科学基金(1212RJZA066;1308RJZA137)资助项目~~

摘　　要：蛋白质与多糖的静电作用是生物体内一个基本医学-化学现象,是实现自组装的主要驱动力,可利用这种非共价作用设计和构筑理想的微结构。以大豆分离蛋白（Soybean Protein Isolates,SPI）和壳聚糖（Chitosan,CS）为原料,采用浊度法考察了配比、溶液p H值、离子强度和温度对SPI与CS在溶液中相互作用的影响。结果显示,由于p H值影响静电作用强度,从而成为影响SPI与CS相互作用的主要因素,其中,当p H值为5.5~6.6时,SPI与CS可以实现有效结合。在较低的离子强度下,有利于形成具有紧凑结构的CS/SPI聚集体,较高离子强度下聚集体发生解离。蛋白质受热发生变性,多肽链上的疏水氨基酸残基暴露在溶液中,导致与壳聚糖链的疏水作用增强。DLS结果显示,CS与SPI自组装形成了分布均一的纳米粒子,变性后的SPI与CS形成的纳米粒子粒径有所增大,分布均一;经戊二醛交联,粒径有所减小。SEM显示,壳聚糖单层膜表面存在龟裂现象,与SPI形成双层膜后龟裂消失;同时,单层膜厚度约为300 nm,双层膜厚度约为500 nm。Electrostatic interactions between proteins and polysaccharides are a fundamental physico-chemical phenomenon in vivo. These interactions are believed to be the main driving force for the self-assembly. In addition, a proper understanding and control of this interaction should enable to design desired structures. Herein, the influences of mass ratios of chitosan （CS） to soybean protein isolates （ SPI）, pH, ion strength and temperature on the interactions between SPI and CS were investigated. The strength of electrostatic interactions between SPI and CS were mainly influenced by the pH values of solutions. The aggregation of SPI and CS occurred at pH varying from 5.5 to 6.6. At the low ion strength, a compact CS/SPI aggregates was formed, whereas, CS/SPI aggregates are dissociated at higher ion strength. As the heating induced denaturation of SPI, hydrophobic amino acid residues on the peptide chains are exposed to the solution, which results in an increase in hydrophobic interactions between CS and SPI. Furthermore, CS/SPI particles and bilayer film were prepared by adjusting the factors above. DIS reveals that nanoparticles are formed by the self-assembly between CS and SPI, and the hydrodynamic diameter is about 200 nm with uniform distribution. After the denaturation of SPI induced by heating, the hydrodynamic diameter is increased. Cross-linking by glutaraldehyde inducs a little decrease of hydrodynamic diameter. SEM results show that there are some cracks in the surface of chitosan monolayer film with thickness of ca 300 nm, and the cracks disappear after the formation of the bilayer film（CS/SPI） with thickness of ca 500 nm.

关 键 词：大豆分离蛋白 壳聚糖 静电作用 纳米颗粒 双层膜 

分 类 号：O636.1[理学—高分子化学]