Production of Steryl Esters from Vegetable Oil Deodorizer Distillates by Enzymatic Esterification

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This work is focused on the production of steryl esters by enzymatic esterification of free fatty acids and sterols present in deodorizer distillates. The enzyme selected, a Candida rugosa lipase, is shown to be able to synthesize steryl esters with a yield of 80%, after 24 h, under optimized conditions. These conditions were determined after studying the influence of various reaction parameters such as enzyme concentration, initial water activity in the reaction medium, and initial free fatty acid:sterol molar ratio (FFA:S), at a fixed temperature of 40 degrees C. The optimal enzyme concentration was found to be 0.5% (w/w), which results from a compromise between the;field of steryl esters formation and the period of time to perform such a task, set as 24 h. The optimal water activity in the reaction medium was found to be in the range between 0.45 and 0.60. The influence of the substrate molar ratio (FFA:S) was also studied, and a minimal ratio of 6:1 was found to be the best. A kinetic mathematical model was established in order to describe the transient state of the reaction system during the enzymatic reaction, as well as to determine the respective kinetic constants, which can be used to predict the evolvement of the composition of the reaction mixture.
Original languageUnknown
Pages (from-to)2865-2875
JournalIndustrial & Engineering Chemistry Research
Issue number5
Publication statusPublished - 1 Jan 2011

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