Air-Water interface: a key place for revealing protein interactions.
Résumé
From their amphiphilic nature, proteins in solution adsorb spontaneously at hydrophobic interfaces. Proteins are thus able to change their conformation, which modifies their surface properties. In the confined space near the interface, these modifications favor the formation of many interactions of weak energy (hydrophobic interactions, hydrogen bonds, Van der Waals interactions), and thus the creation, in the interface plane, of a network of intermolecular interactions. Adsorbed proteins can thus, in favorable conditions, constitute at the interface a continuous film with visco-elastic properties. These mechanical properties contribute to the stabilization of the interface created in multiphasic systems such as foams. Our work focuses on the behavior at the air-water interface and, if needed the foam properties, of some model globular proteins: ovalbumin, lysozyme, ovotransferrin, β-lactoglobulin… The aim of our work is to understand, using these models, how protein properties (structure, biochemistry, physico-chemistry), potentially adjusted by the physico-chemical environment, chemical changes or thermo-mechanical treatments, take part in the interfacial behavior, film characteristics and macroscopic proprieties of foams (overrun, stability, texture). Besides, in systems where several proteins with different properties (size, hydrophobicity, charge, conformation flexibility,…) coexist, we look to understand how the interactions between proteins enhance behaviors that cannot be considered as the sum of the single behaviors. The issue over time is to control technological parameters to improve texture properties in relation to foaming capacity.