Characterisation 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 adsorption 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-called 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 thickness are estimated. (C) 1998 Elsevier Science B.V.