Enzymatic production of xylose esters using degummed soybean oil fatty acids following a hydroesterification strategy

Abstract

The enzymatic synthesis of xylose fatty acid esters was carried out in two steps: hydrolysis of degummed soybean oil (DSO) and esterification of the produced and purified free fatty acids (FFA) with xylose. Different lipases immobilized on a hydrophobic support were evaluated in the hydrolysis of DSO and an experimental design was used to optimize the reaction. Eversa® Transform 2.0 (EV-Purolite) yielded 93% conversion after 6 h using biocatalyst load of 6.53 wt%, water/oil mass ratio of 5.5 and temperature of 48.4 °C. High operational stability for EV-Purolite was found using a sequential batch strategy and the possibility of concentrating glycerol. In the esterification stage, lipase from Thermomyces lanuginosus (TLL-Purolite) and lipase B from Candida antarctica showed better performance than lipase from porcine pancreas and EV-Purolite. About 17% of FFAs (0.85 molecules of FAA per xylose molecule) was consumed using an enzyme load of 5 wt% of TLL-Purolite and FFA/xylose molar ratio of 5. Sequential esterification batches showed low operational stability of TTL-Purolite due to the desorption of TLL from the support. The final mixture of the reaction medium containing xylose fatty acid esters showed emulsifying properties similar to those of commercial surfactant.