Kinetics of lipase-catalyzed hydrolysis of olive oil

Lipase-catalyzed hydrolysis of olive oil has been studied in the absence of added emulsifier. The kinetic analysis of the lipase-catalyzed hydrolysis reaction was found to be possible in this system. The amount of fatty acids produced was linearly proportional to the enzyme concentration of 0.1 mg protein ml(-1). The specific enzyme activity was 2500 units mg(-1) enzyme, at 37 degrees C in 25 mM phosphate buffer, pH 7.0, at 50% (v/v) olive oil concentration. The hydrolytic reaction obeys Michaelis-Menten kinetics with V-max,V-app and K-m,K-app of 3470 units mg(-1) enzyme and 16.7% (v/v), respectively. Maximum activity was obtained at pH 7.0, at low buffer ionic strength, 25 mM and 37 degrees C. The enzyme was found to be inhibited by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and o-phthaldialdehyde in a biphasic manner. These results suggested that carboxyl groups and lysyl and cysteinyl residues might be involved in the catalytic site or substrate-binding site of this enzyme. (C) 1997 Canadian Institute of Food Science and Technology. Published by Elsevier Science Ltd.