Lipase-catalyzed production of wax esters

Abstract

The lipase (triacylglycerol acylhydrolase, E.C. 3.1.1.3) catalyzed synthesis of wax esters has been investigated via two different approaches. All studies were performed using an immobilized 1,3-specific lipase [Lipozyme from Novo Industries (Montréal, Québec, Canada)]. The first approach involves reacting stoichiometric amounts of a fatty acid and stearyl alcohol in the presence of lipase. The medium is solvent-free, which allows for high substrate concentrations (1.55 M) and use of 5% (w/w) Lipozyme. In this reaction, maximum wax ester synthesis was found to be dependent upon the efficient removal of the water produced by the reaction. Under optimal conditions, yields of 100% were routinely reached after only 2 hr. The medium was then exclusively composed of the wax and the enzyme, no purification was required. The second method involves alcoholysis of a triglyceride, in this case triolein, with stearyl alcohol to produce 1,2-diolein, 2-monoolein and the wax ester of oleic acid. Again, no organic solvent was used. The wax ester yield was found to be directly dependent upon the alcohol concentration that was used to modulate the outcome of the reaction towards either the wax or the partial glycerides. The process was applied to the synthesis of waxes from high erucic acid rapeseed oil.