title: Self-assembly of monoglycerides in beta-lactoglobulin adsorbed films at the air-water interface. Structural, topographical, and rheological consequences.
abstract: In this work, we have analyzed the structural, topographical, and surface dilatational characteristics of pure beta-lactoglobulin adsorbed films and the effect of the self-assembly of monoglycerides (monopalmitin or monoolein) in beta-lactoglobulin films at the air-water interface. Measurements were performed in a single device that incorporates a Wilhelmy-type film balance, Brewster angle microscopy, and interfacial dilatational rheology. The structural and topographical characteristics of beta-lactoglobulin adsorbed and spread films are similar. However, the surface dilatational modulus of beta-lactoglobulin films shows a complex behavior depending on film formation. The self-assembly of monoglyceride in a beta-lactoglobulin adsorbed film has an effect on the structural, topographical, and dilatational properties of the mixed films, depending on the interfacial composition and the surface pressure (pi). At low pi, a mixed film of monoglyceride and beta-lactoglobulin may exist. At high pi (after the collapse of beta-lactoglobulin), the mixed films are dominated by monoglyceride molecules. However, the small amounts of collapsed beta-lactoglobulin have a significant effect on the surface dilatational properties of the mixed films. Protein displacement by monoglyceride is higher for monopalmitin than for monoolein. However, some degree of interaction exists between proteins and monoglycerides, and these interactions are more evident in adsorbed films than in spread films.
authors.affiliation: Departamento de Ingeniería Química, Facultad de Química, Universidad de Sevilla, C/Professor García Gonzalez 1, 41012-Seville, Spain. jmrodri@us.es
authors.forename: Juan M
authors.initials: JM
authors.lastname: Rodríguez Patino
authors.forename: Marta Cejudo
authors.initials: MC
authors.lastname: Fernandez
authors.forename: M Rosario
authors.initials: MR
authors.lastname: Rodríguez Niño
authors.forename: Cecilio Carrera
authors.initials: CC
authors.lastname: Sanchez
mesh_terms: D000327:Adsorption; D000388:Air; D001672:Biocompatible Materials / Q000737:chemistry; D001709:Biotechnology / Q000379:methods*; D002627:Chemistry, Physical / Q000379:methods; D005989:Glycerides / Q000737:chemistry; D007782:Lactoglobulins / Q000737:chemistry*; D050178:Monoglycerides / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry; D012212:Rheology / Q000379:methods*; D013499:Surface Properties; D014867:Water
chemical_list: D001672:Biocompatible Materials; D005989:Glycerides; D007782:Lactoglobulins; D050178:Monoglycerides; D011506:Proteins; D014867:Water; C027735:palmitoyl glycerol