Convenient enzymatic preparation of conjugated linoleic acid alkyl esters with C6–C22 alcohols

A fast and effective enzymatic process was developed for preparing CLA C6–C22 alkyl esters using immobilized Candida antarctica lipase B (Novozym 435). The reaction parameters (temperature, amount of starting materials and enzyme, effect of water removal during the reaction) were optimized. The re-use study showed that the enzyme can be used at least ten times without significant loss in its activity. Reactions between equimolar amounts of starting materials with 8.9% Novozym 435 (w/wCLA) at 65 °C in vacuum (20 mbar) for 1.5 h resulted in almost quantitatively (>95%) wax esters needing no further treatment. At room temperature, CLA esters with long chain (≥18 °C) saturated alcohols are solids.