Formation of dairy fouling deposits on food contact surfaces

This study aimed to compare microbiological, biochemical and physical methods to quantify dairy fouling deposits. The influence of factors affecting dairy fouling formation is investigated by selected methods with respect to material type (polytetrafluoroethylene and stainless steel) and temperature (4 and 20 °C) for a defined time. The factors were investigated using nonmicrobiologically caused and microbiologically caused dairy deposits formed by UHT and pasteurised milk inoculated with Pseudomonas fragi. Both deposit types exhibited different adhesion behaviours. The highest positive correlation coefficient was found between biochemical and microbiological methods (0.932) obtained at both incubation temperatures after 24 and 48 h.