Fouling is the formation of undesirable layers composed mostly of proteins and minerals on heating surfaces, generally made of stainless steel. This phenomenon significantly affects the performance of operations and the quality of products in the dairy industry. The formation dynamics of these protein-based deposits is linked to the denaturation and aggregation of whey proteins by reactions in the liquid flow and on the surface of equipment. Furthermore, the growth of solid layers is favored by the presence of minerals in the initial solution serving as bridges between activated aggregates. However, the studies available in the literature are based on an "off-line" analysis of solid deposits, therefore fail to shed light on the specific role of each component on the different stages of fouling. Whey protein isolate (WPI) is able to aggregate and by studying the kinetics of denaturation of whey proteins β-lactoglobulin that will allow to understand the mechanisms of thermal fouling in falling film evaporators.