β-Lactoglobulin Fouling and its Removal upon Rinsing and by SDS as Influenced by Surface Characteristics, Temperature and Adsorption Time

摘要

The extensive fouling common in the food industry puts high demands on equipment cleaning. The adsorption of β-lactoglobulin and its removal by the anionic surfactant sodium dodecyl sulphate (SDS) were followed at pH 6.0 using in situ ellipsometry. Hydrophilic chromium oxide and stainless steel together with hydrophobic methylated silica were studied at different temperatures. Differences between chromium oxide and steel were small, while hydrophobic silica showed significantly different initial adsorption kinetics and adsorbed amounts. Also, the temperature-dependence of the amount desorbed upon rinsing as well as of the overall cleanability differed greatly. At around the β-lactoglobulin denaturation temperature, multilayer build-up at the surface was seen, and the cleanability was very low. Of two protein adsorption times employed, the longer resulted, for metal oxide surfaces, in less desorption during rinsing.