HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY AND ULTRAFILTRATION OF WHEY PROTEINS WITH INORGANIC POROUS MATERIALS COATED WITH POLYVINYLIMIDAZOLE DERIVATIVES

A coated ultrafiltration membrane was developed which allows the highly selective extraction of lactalbumin from a whey protein mixture. A permeate containing only lactalbumin was obtained using inorganic membranes coated with polyvinylimidazole derivatives containing both ionic and hydrophobic groups. The phenomena involved were analysed with high-performance liquid chromatographic supports bearing similar coatings. With the hydrophobic layer, the selectivity enhancement can be explained through mixed interactions with whey proteins; increasing fouling is due to both lactoglobulin and lactalbumin contributions to the build-up of the boundary layer at the wall of the derivatized membrane.