title: Adsorption of proteins at the aqueous solution/alkane interface: Co-adsorption of protein and alkane.
abstract: The equations of state, adsorption isotherms and functions of the distribution of protein molecules in liquid interfacial layers with respect to molar area and the equations for their viscoelastic behavior are presented. This theory was used to determine the adsorption characteristics of β-casein and β-lactoglobulin at water/oil interfaces. The experimental results are shown to be describable quite adequately by the proposed theory with consistent model parameters. The data analysis demonstrated that the β-casein molecule adsorbed at equilibrium conditions is more unfolded as compared with dynamic conditions, and this fact causes the significant increase of the adsorption equilibrium constant. The theory assumes the adsorption of protein molecules from the aqueous solution and a competitive adsorption of alkane molecules from the alkane phase. The comparison of the experimental equilibrium interfacial tension isotherms for β-lactoglobulin at the solution/hexane interface with data calculated using the proposed theoretical model demonstrates that the assumption of a competitive adsorption is essential, and the influence of the hexane molecules on the shape of the adsorption isotherm does in fact exist.
authors: Max-Planck-Institut für Kolloid- und Grenzflächenforschung, 14424 Potsdam, Germany.
authors: R
authors: R
authors: Miller
authors: Institute of Colloid Chemistry and Chemistry of Water, Kiev 03680, Ukraine.
authors: E V
authors: EV
authors: Aksenenko
authors: Donetsk Medical University, Donetsk 83003, Ukraine.
authors: I I
authors: II
authors: Zinkovych
authors: Donetsk Medical University, Donetsk 83003, Ukraine.
authors: V B
authors: VB
authors: Fainerman
mesh_terms: D000327:Adsorption; D000473:Alkanes / Q000737:chemistry*; D002364:Caseins / Q000737:chemistry*; D007782:Lactoglobulins / Q000737:chemistry*; D011312:Pressure; D012996:Solutions; D013499:Surface Properties; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D000473:Alkanes; D002364:Caseins; D007782:Lactoglobulins; D012996:Solutions; D014867:Water
keywords: Competitive adsorption of protein and hexane molecules; Drop profile analysis tensiometry; Equation of state; Interfacial dilational viscoelasticity; Water/hexane interface; Whey protein adsorption