HYDROLYSIS OF COCONUT OIL (COCOS-NUCIFERA L.) BY SPECIFICITY AND NO POSITIONAL SPECIFICITY ENZIMES

The characteristic fatty acid composition of coconut oil provides main ly short-and medium-chain fatty acids when incorporated to the diet. T hese fatty acids have nutritional advantages because their metabolic d isposition allows the rapid obtention of energy, mainly at the hepatic level. The obtention of short-and medium-chain fatty acids from cocon ut oil as substrate, may be of importance because the different nutrit ional, pharmacological, and technological uses of these fatty acids. I n the present work, the effect of two type of lipases on the hydrolysi s of coconut oil was studied; a lipase obtained from Candida cylindrac ea showing no positional specificity, and a lipase from Mucor miehei w ith sn-1',3' specificity in its free and immobilized form (Lipozyme IM -20), The lipase from Candida cylindracea allows the hydrolysis of 85% -90% of the triacylglycerols after 47-50 hours, the fatty acid composi tion of the hydrolyzate being similar to the composition of the oil. T he remaining monoacylglycerols show a prevalent composition of short- (C6-C8) -and medium-chain (C10-C14) fatty acids. Lipase from Mucor mie hei allows 65% of hydrolysis, which is obtained after 30 hours of incu bation when the free form of the lipase is assayed, and after 10 hours for the immobilized form (Lipozyme IM-20). The fatty acid composition of the hydrolyzate is similar for the two enzymes and different to th e composition of the oil, being C8-C14 the most prevalent fatty acids. The remaining monoacylglycerol, as product of the action of both form s of the enzyme, is almost enterely composed by lauric acid (C12:0), i mplicating that the sn-2' position is the most favoured for this fatty acid in the coconut oil triacylglycerols. The usefullness of lipases for the obtention of especific fractions of some fatty acids is discus sed. The utility of the lipase from Mucor miehei for the obtention enr iched fractions of lauric acid, which can be liberated after saponific ation, is also discussed.