Martinez María J, Sánchez Cecilio Carrera, Patino Juan M Rodríguez, Pilosof Ana M R
Departamento de Industrias, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria (1428), Buenos Aires, Argentina.
Colloids Surf B Biointerfaces. 2009 Jan 1;68(1):39-47. doi: 10.1016/j.colsurfb.2008.09.006. Epub 2008 Sep 18.
The aim of this work was to study the interactions and adsorption of caseinoglycomacropeptide (GMP) and GMP:beta-lactoglobulin (beta-lg) mixed system in the aqueous phase and at the air-water interface. The existence of associative interactions between GMP and beta-lg in the aqueous phase was investigated by dynamic light scattering, differential scanning calorimetry (DSC), fluorometry and native PAGE-electrophoresis. The surface pressure isotherm and the static and dynamic surface pressure were determined by tensiometry and surface dilatational properties. The results showed that GMP presented higher surface activity than beta-lg at a concentration of 4%wt but beta-lg showed higher film forming ability. In the mixed systems beta-lg dominated the static and dynamic surface pressure and the rheological properties of interfacial films suggesting that beta-lg hinders GMP adsorption because, in simple competition, GMP should dominate because of its higher surface activity. The surface predominance of beta-lg can be attributed to binding of GMP to beta-lg in the aqueous phase that prevents GMP adsorption on its own.
本研究旨在探讨酪蛋白糖巨肽（GMP）以及GMP与β-乳球蛋白（β-lg）混合体系在水相和空气-水界面的相互作用及吸附情况。通过动态光散射、差示扫描量热法（DSC）、荧光法和非变性聚丙烯酰胺凝胶电泳（PAGE）研究了水相中GMP与β-lg之间缔合相互作用的存在情况。采用张力测定法和表面扩张特性测定了表面压力等温线以及静态和动态表面压力。结果表明，在4%wt浓度下，GMP比β-lg具有更高的表面活性，但β-lg表现出更高的成膜能力。在混合体系中，β-lg主导了静态和动态表面压力以及界面膜的流变特性，这表明β-lg阻碍了GMP的吸附，因为在简单竞争中，由于GMP具有更高的表面活性，本应占据主导地位。β-lg在表面的优势可归因于水相中GMP与β-lg的结合，从而阻止了GMP自身的吸附。
