Non-invasive monitoring of protein adsorption and removal in a turbulent flow cell.
A flow cell was designed for continuous non-invasive measurements of macromolecular adsorption and removal under well-defined flow conditions. The adsorption of the protein beta-lactoglobulin to stainless steel surfaces and its subsequent detergent-induced removal were followed in the flow cell using in situ ellipsometry under both laminar and turbulent conditions. Factors varied include the cleaning agent type and concentration, the flow rate and the protein concentration. In addition, the experiments studying different cleaning agents were repeated in a stirred cuvette system employed in previous work. The ellipsometer as well as the experimental set-ups are described, with particular emphasis on the flow cell design. Evaluation of the results is done by comparing the amounts of protein adsorbed from solution, the initial adsorption rates, the amounts removed in water or detergent and the residual amounts after cleaning. The results are discussed in terms of beta-lactoglobulin unfolding, preferential adsorption, different states of adsorbed molecules, additional physicochemical aspects and hydrodynamic characteristics.
Karlsson
CA
Food Engineering, Lund University, PO Box 124, S-221 00, Lund, Sweden
Wahlgren
MC
Trägårdh
AC