本课题以传统发酵乳制品中乳酸菌所产胞外多糖及聚合乳清蛋白为研究对象，通过（一）采用GC-MS、HPGPC、红外光谱、核磁共振和电镜扫描等技术对胞外多糖的结构特性进行研究；（二）采用共聚焦激光扫描显微镜、流变仪等观察混合体系的微观结构,探讨乳清蛋白胞外多糖混合体系的形成机理；（三）采用静态光散射表征多糖分子的均方根旋转半径及重均分子量,利用Vrij建立的排空相互作用理论模型预测不同乳清蛋白聚集体不同多糖混合体系的相边界，进一步揭示乳清蛋白胞外多糖混合体系的形成机理。通过本课题的研究不仅能够为聚合乳清蛋白与乳酸菌多糖在乳制品中协同应用提供理论依据，同时对提高发酵乳制品品质，解决贮藏运输中的问题具有一定的指导意义。

This subject regards extracellular polysaccharide produced by the lactic acid bacteria with capacity of producing EPS from naturally fermented milk and polymerized whey protein as the research objects.This paper will be carried out from three aspects: (a) studying structural characteristics of extracellular polysaccharide by GC-MS, HPGPC, IR and NMR spectroscopy and scanning electron microscopy; (b) observating microstructure and rheological properties of polymerized whey protein - extracellular polysaccharide mixtures by using confocal laser scanning microscope and rheometer and discussing the formation mechanism of polymerized whey protein - extracellular polysaccharide mixtures; (c) predicting phase boundary of polymerized whey protein and extracellular polysaccharide mixtures, furtherly reveal the formation mechanism of the mixtures. The research will provide a theoretical basis for collaboration application of polymerized whey protein and extracellular polysaccharide in dairy products and contribute to the quality improvement of fermented dairy products and solve the problems in storage and transportation.