Esterification of glucose fatty acids of coconut oil catalyzed by Candida rugosa lipase EC 3.1.1.3 immobilized on an Indonesia's natural zeolite matrix

Glucose fatty acid esters can be served as a low calories fat replacer and emulsifier. The study aims to synthesize esters enzymatically catalyzed by immobilized lipase on the activated natural zeolite. Optimal immobilization carried out at temperatures of 37°C, with a ratio of enzyme: zeolite = 1: 3 (w / w) gave 74.81 % loading efficiency. Immobilization occurs on the surface of the zeolite are shown from the results of FESEM analysis with the SE and BSE detectors. Optimum activity of the immobilized enzyme was 35.27 % compared to free lipase. Fatty acid used is hydrolysis products of coconut oil with the largest content of lauric acid (54.10 %). The optimum conditions of esterification occur at temperatures of 40°C, the ratio of glucose: fatty acid 1:60, incubation time of 16 hours and weighs 1.1 g molecular sieve with a maximum product conversion of 8.75%. Degree of esterification product is still low, so that the esterification product is only suitable for emulsifier instead of fat replacer.