Technical Abstract: The study of protein adsorption on the membrane surface is of great importance to cheese-making processors that use polymeric membrane-based processes to recover whey protein from the process waste streams. Quartz crystal microbalance with dissipation (QCM-D) is a lab-scale, fast analytical technique that can precisely monitor and quantify the amount of proteins adsorbed onto the polymer surface in real time. The ability of the software that accompanies the instrument to predict the minute amount of the mass of the protein on the surface and the structural properties of the adsorbed protein requires a suitable mathematical model to convert the data of frequency and dissipation shift responses generated from the QCM-D apparatus into the mass and viscoelastic properties of the proteins adsorbed on the surface at given times. In this study, data recorded by a QCM-D apparatus were fitted into the Kevin-Voigt model, to quantify the whey protein adsorption on the polyethersulfone membrane surface.