ABSTRACTThe influence of enzymatic modification with Alcalase was studied on surface hydrophobicity, molecular weight distribution and emulsifying properties of ten hydrolysates from sardine differing in degree of hydrolysis. Surface hydrophobicity was evaluated fluorometrically using 1 anilino‐8‐naphthalenesulfonate (ANS); molecular weight distribution was determined by gel chromatography on a Superfine Sephadex G50. Emulsifying capacity and stability were evaluated as functions of pH values and product concentration, in comparison with sodium caseinate. Results showed emulsifying properties, surface hydrophobicity and the high molecular weight fraction decreased as degree of hydrolysis increased. Thus production of hydrolysates with desired molecular structures and emulsifying properties is possible.