ENZYMATIC PREPARATION OF MONO-STEARIN AND DI-STEARIN BY GLYCEROLYSIS OF ETHYL STEARATE AND DIRECT ESTERIFICATION OF GLYCEROL IN THE PRESENCE OF A LIPASE FROM CANDIDA-ANTARCTICA (NOVOZYM-435)

Mixtures of 1(3)-monostearin and distearin were prepared by direct esterification of glycerol with stearic acid or transesterification using ethyl stearate as acyl donor in the presence of Candida antarctica lipase (Novozym 435) using a variety of solvents of differing polarity. In all cases, the transesterification resulted in higher product yields. In n-heptane as reaction medium the addition of water (3%) was: essential for high product yields, with mono- and distearin being produced in almost equal amounts. Using more polar solvents as reaction media, such as acetonitrile or acetone, again the highest yields were obtained in the transesterification mode; employing these solvents the reactions were much more selective towards the formation of monostearin.