4-FACTOR RESPONSE-SURFACE OPTIMIZATION OF THE ENZYMATIC MODIFICATION OF TRIOLEIN TO STRUCTURED LIPIDS

The ability of an immobilized lipase to modify the fatty acid composit ion of (88.8% C-18:1, 4.3% C-16:0, 3.1% C-18:0, and 3.8% C-18:2 as det ermined by gas chromatography, and approximately 90% triolein) in hexa ne by incorporation of a medium-chain fatty acid, capric acid (C-10), to form structured triacylglycerol was studied. Response surface metho dology was used to evaluate the effect of synthesis variables, such as reaction time (12-36 h), temperature (25-65 degrees C), molar substra te ratio of capric acid to triolein (2:1-6:1), and enzyme amount (10-3 0% wt% of triacylglycerol), on the yield of structured lipid. Optimiza tion of the transesterification was attempted to obtain maximum yield of structured lipid while using the minimum molar substrate ratio and enzyme amount as much as possible. Computer-generated contour plot int erpretation revealed that a relatively high molar substrate ratio (6:1 ) combined with low enzyme amount (10%) after 30 h of reaction at 25 d egrees C gave optimum incorporation of capric acid. A total yield for combined mono- and dicaproolein of up to 100% was obtained.