Deposition of heated whey proteins on a chromium oxide surface

Abstract

Whey protein solutions were given different heat treatments after which their deposition on a chromium oxide surface (the outer layer of stainless steel) was measured by reflectometry. The deposition was studied under controlled flow conditions by using a stagnation point flow configuration. The rate of deposition is related to a model for heat-induced denaturation. It predicts an activation of β-lactoglobulin (β-lg) and subsequent aggregation. Deposition of more than a monolayer requires the presence of activated β-lg molecules near the surface. It was possible to quantify the rate of deposition by relating it to the concentration of activated molecules. The deposition process is determined by a combination of factors: the reaction by which the activated molecules are formed; their transport to the surface; and the subsequent sticking probability.