Functional improvement of alginic acid by conjugating with beta-lactoglobulin

Two bovine beta-lactoglobulin-alginic acid (beta-LG-ALG) conjugates were prepared to improve the function of ALG by using water-soluble carbodiimide and the Maillard reaction. Fluorescence studies suggested that the conformation around Trp had been changed in each conjugate and that the surface of each conjugate was covered with polysaccharide chain. Structural analyses with monoclonal antibodies indicated that the conformation around 15Val-29IIe (beta-sheet) in each conjugate had changed, while the native structure was maintained around 125Thr-135Lys (alpha-helix). After conjugating with beta-LG, ALG showed retinol-binding and high emulsifying ability. The aggregating property of ALG in acid and in the presence of Ca2+ was improved in each conjugate.