Lipolysis of butter oil by immobilized lamb pregastric esterase: I. Uniresponse kinetics - pH and temperature effects

Lamb pregastric esterase, immobilized by physical adsorption on microporous polypropylene in a hollow fiber reactor, has been employed to effect the c ontinuous hydrolysis of the triglycerides in butter oil. Experimental data were obtained at temperatures from 35 to 45 degreesC and pH values from 5.5 to 6.5. The overall rate of hydrolysis was fastest at 40 degreesC and a pH of 6.0. Nonlinear regression methods were employed to determine the kineti c parameters of rate expressions based on a generic Ping-Pong Bi Bi mechani sm. 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 hydr olysis reaction.