SURFACE-PROPERTIES OF PROTEIN ALCOHOLIC SOLUTIONS .3. AGING EFFECT

The transient surface dynamic properties of alcoholic solutions of BSA and beta-casein are studied by the longitudinal wave method over a pe riod of 4 h. The aging effect is the most influential on the surface t heology when the ethanol content is 5%, v/v. It affects mostly the app arent surface viscosity. A parametric analysis shows that the surface theology evolution is assigned to change of the residual elasticity an d of the constant rate of the surface relaxation. This has been relate d to the protein unfolding properties and to the influence of ethanol on the protein secondary structure. (C) 1994 Academic Press, Inc.