CHARACTERIZATION OF THE INITIAL PERIOD OF PROTEIN ADSORPTION BY DYNAMIC SURFACE-TENSION MEASUREMENTS USING DIFFERENT DROP TECHNIQUES

A model is derived for the initial state of the formation of protein a dsorption layer. This model considers the balance of protein molecules adsorbed at the drop interface and solved in the bulk of a drop. The mass balance allows estimation of the adsorbed amount, the adsorption layer thickness, and the diffusion coefficient at the end of the so-ca lled induction time. For a globular (human serum albumin) and a native protein (beta-casein) these parameters are determined and agree with data from literature. For beta-casein the effect of bulk concentration on the degree of denaturation and the minimum adsorption layer thickn ess are estimated. (C) 1998 Elsevier Science B.V.