Increased rate of lipase-catalyzed saccharide-fatty acid esterification bycontrol of reaction medium

Through proper selection of initial conditions and control of the reaction medium composition, a productivity rate over 10-fold higher than that previ ously reported was achieved for lipase-catalyzed fructose-oleic acid esteri fication. From a screening process, tert-butanol (t-BuOH) was selected as t he most effective solvent for cosolubilizing fructose and oleic acid during the initial stage of the reaction. A t-BuOH concentration of 0.35-0.55 w/w produced the highest rate and extent of reaction at 60 degrees C. Neither water addition nor removal applied to initial reaction materials improved t he rate. Since both fructose-oleic acid mono- and diester promoted higher f ructose solubility than either oleic acid or oleic acid/t-BuOH mixtures, t- BuOH was not needed during the latter stage of the reaction. Also, the pres ence of t-BuOH hindered the removal of water by free evaporation. Thus, com plete removal of t-BuOH. during the middle-to-latter stage of reaction was found to enhance the reaction rate. In addition, the introduction of fructo se to the reactor in small batchwise increments accelerated the reaction, T he monoester to diester ratio decreased during the initial and middle stage s of the reaction owing to the disappearance of t-BuOH, but increased sligh tly during the later stages presumably because of the ester formation. Pape r no. J9170 in JAOCS 76, 1495-1500 (December 1999).