title: Interactions in the aqueous phase and adsorption at the air-water interface of caseinoglycomacropeptide (GMP) and beta-lactoglobulin mixed systems.
abstract: 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.
authors.affiliation: Departamento de Industrias, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria (1428), Buenos Aires, Argentina.
authors.forename: María J
authors.initials: MJ
authors.lastname: Martinez
authors.forename: Cecilio Carrera
authors.initials: CC
authors.lastname: Sánchez
authors.forename: Juan M Rodríguez
authors.initials: JM
authors.lastname: Patino
authors.forename: Ana M R
authors.initials: AM
authors.lastname: Pilosof
mesh_terms: D000327:Adsorption; D000388:Air; D002152:Calorimetry, Differential Scanning; D004591:Electrophoresis, Polyacrylamide Gel; D005470:Fluorometry; D007782:Lactoglobulins / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry*; D013499:Surface Properties; D014867:Water
chemical_list: D007782:Lactoglobulins; D010446:Peptide Fragments; D014867:Water