中性水相介质中开菲尔胞外多糖与乳清蛋白的相互作用

Interaction between kefiran and whey protein in neutral aqueous medium

以中性水相为介质,制备开菲尔胞外多糖(Kefiran)-乳清蛋白(whey protein,WP)共混体系,采用扫描电镜、激光粒径仪、荧光光谱分光光度计和流变仪,通过对共混体系的粒径、电位绝对值、微观结构、荧光光谱和流变特性进行测定,研究共混体系中Kefiran与乳蛋白的相互作用。研究结果表明,在Kefiran/WP混合体系中,通过Kefiran与WP之间相互作用,粒径增大,Zeta-电位绝对值减小,紫外吸收峰强度和荧光强度均降低。微观结构表明,与乳清蛋白表面粗糙疏松的颗粒状结构和具有薄膜特点的Kefiran表面光滑、结构疏松、间或呈网状结构相比,Kefiran-WP混合体系呈碎片状、表面紧密光滑的聚合物结构。流变学特性表明,Kefiran与WP之间出现耗尽作用,使得混合体系的表观黏度增加,凝胶特性增强。而Kefiran-WP混合体系的稳定性明显更依赖于频率。

Kefiran-whey protein(WP) mixed system was prepared in neutral aqueous phase medium.The interaction between kefiran and WP in the mixed system was studied by measuring the particle size,potential absolute value,microstructure,fluorescence spectrum,and rheological properties by scanning electron microscope,laser particle size analyzer,fluorescence spectrophotometer,and rheometer.The results showed that the particle size increased,the absolute value of zeta potential decreased.The UV absorption peak intensity and fluorescence intensity all decreased through the interaction between kefiran and WP in the kefiran-WP mixed system.The microstructure showed that compared with the rough and loose granular structure of WP and the smooth and loose surface and occasionally reticular structure of kefiran with the characteristics of thin film,the kefiran-WP mixed system has a fragmented,compact,and smooth polymer structure.The rheological properties showed that the depletion between kefiran and WP improved the apparent viscosity and enhanced the gel properties of the mixed system.The stability of kefiran-WP mixed solution obviously depends on frequency.