Lipolysis of Butter Oil by Immobilized Lamb Pregastric Esterase: I. Uniresponse Kinetics—pH and Temperature Effects

Abstract

Lamb pregastric esterase, immobilized by physical adsorption on microporous polypropylene in a hollow fiber reactor, has been employed to effect the continuous hydrolysis of the triglycerides in butter oil. Experimental data were obtained at temperatures from 35 to 45°C and pH values from 5.5 to 6.5. The overall rate of hydrolysis was fastest at 40°C and a pH of 6.0. Nonlinear regression methods were employed to determine the kinetic parameters of rate expressions based on a generic Ping-Pong Bi Bi mechanism. The best nonlinear fit of the data was consistent with a mechanism that assumes that acylation of the enzyme is the rate-limiting step in the hydrolysis reaction.