J. Agric. Food Chem. 45 : 703-708 (1997)

Functional Improvement of Beta-Lactoglobulin by Conjugating with Alginate Lyase-Lysate

M. Hattori, A. Ogino, H. Nakai and K. Takahashi

Department ofApplied Biological Science,
Faculty of Agriculture,
Tokyo University of Agriculture and Technology
Tokyo 183, Japan

Bovine beta-lactoglobulin-alginic acid oligosaccharide (BLG-ALGO) conjugate was prepared by the Maillard reaction to improve the function of BLG. The molar ratio of BLG to ALGO in the conjugates was 1 : 7. The isoelectric point of the conjugate was 4.55, which is lower than that of BLG. Fluorescence studies suggested that the conformation around Trp had changed in the conjugate and that the surface of the conjugate was covered with saccharide chain. Structural analyses with monoclonal antibodies indicated that the conformation around 15Val-29Ile (beta-sheet) in the conjugate had changed, while native structure was maintained around 125Thr-135Lys (alpha-helix). By conjugation with ALGO, BLG was endowed with high heat stability. The emulsifying activity and the aggregating property of BLG was improved in the conjugate.