Fouling in heat exchangers in the food industry causes not only the reduction of the overall system performance, but
also a reduction of food quality due to overheating or insufficient heating resulting in potential risk of microbiological
contamination. A measure to avoid or at least mitigate fouling is the modification of the heat transferring surface.
In order to understand the interaction deposit-surface stainless steel was coated by plasma enhanced chemical
vapor deposition and the deposition behavior of whey protein, calcium phosphate and a combination of both was
investigated. DLC (diamond-like carbon) coatings, namely a-C:H, a-C:H:Si and a-C:H:Si:O, were fouled at an initial
surface temperature of 80 and 120/105 ◦C and the impact of the surface modification on the fouling resistance,
the amount and type of deposit formed and the deposit composition were assessed. The results showed that the
surface energy properties affected the first fouling layer formation as well as further stages of build-up and the
deposit structure, principally at the lower surface temperature. Moreover the electron donor component significantly
influenced the final fouling resistance as well as the deposit mass, suggesting an optimum value of − for which
deposits have lower adhesive and cohesive strengths and the fouling is minimal.