LIPASE-MEDIATED ACYL-EXCHANGE REACTIONS WITH BUTTEROIL IN ANHYDROUS MEDIA

Conditions optimum for porcine pancreatic lipase catalyzed acyl-exchange reactions between a free fatty acid (FFA), undecanoic acid, and butteroil in anhydrous media were established. No solvent was required for reaction, indicating that butteroil could act as dispersant as well as substrate in reactive mixtures. Optimum temperature and pH for the reaction were 70-degrees-C and 6.5 to 7.0, respectively. The addition of up to 550 mM water to reactive mixtures had little influence on the initial rates of acyl-exchange, but shifted the reaction equilibrium to favor net hydrolysis. Optimal FFA concentration for acyl-exchange was 250 mM in terms of initial reaction rates, and substrate inhibition by FFA was apparent at levels up to 1000 mM. In terms of % reaction yield and absolute reaction yield after 18 hr, 50 mM and 250 mM FFA, respectively, were optimum. Initial reaction rates for acyl-exchange between two model triacylglycerides indicated that esterified fatty acids were better substrates than FFA under the conditions evaluated.