Lysine residues offer a convenient way of incorporating various chemical groups on to the surface of proteins. The effect of introducing chemical groups of various nature on the protein surface on its adsorption properties at the alumina/water interface have been studied. Hydrophilic sugar groups have been introduced by glycosylation, hydrophobic meihyl group has been introduced by reductive alkylation and negatively charged phosphate group has been introduced by pyridoxylation of β-lactoglobulin. The adsorption density of these modified proteins on alumina were compared with that of the unmodified protein. It has been found that all of the above modifications significantly reduced the affinity of β-lactoglobulin for the solid surface at all the three pH's studied here.