2026-04-29T01:08:53Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/45672022-04-29T12:02:46Zcom_10259_4244com_10259_5086com_10259_2604col_10259_4245

00925njm 22002777a 4500 dc Melgosa Gómez, Rodrigo author Sanz Díez, Mª Teresa author García Solaesa, Ángela author Paz Barragán, Esther de author Beltrán Calvo, Sagrario author Lamas, Daniela L. author 2017-01 Supercritical carbon dioxide (SC-CO2) has been used as green solvent in the lipase-catalyzed ethanolysis of fish oil by Lipozyme RM IM at mild, non-oxidative conditions and with no solvent residues. The effect of experimental conditions, initial substrate ethanol/oil molar ratio (2–38), pressure (7.5–30 MPa), and temperature (323.15–353.15 K) on equilibrium conversion, reaction rate and oxidative status of the products has been studied. No ethanol inhibition has been observed at high concentrations of ethanol, when putting in contact first the fish oil with the enzyme avoiding direct contact between the biocatalyst and ethanol. Operating pressure affected positively the reaction performance in the range investigated. Visual observation of the phase behaviour of the initial reaction mixture showed an “expanded liquid phase” that helped enhancing reaction rate, and a gas phase. Raising temperature accelerated the reaction up to a limit (343.15 K), observing higher enzyme thermal stability than in other reaction media (313.15 K). However, lipid oxidation increases with temperature. Up to 86 ± 1% FAEE yield has been found at MR = 6:1, 30 MPa and 323.15 K. Kinetic data have been correlated by using a mathematical model based on the elementary reactions of the 3-step transesterification. Kinetic rate constants, apparent activation volumes and energies are reported for the first time for a lipase-catalyzed ethanolysis reaction in SC-CO2. 2212-9820 http://hdl.handle.net/10259/4567 10.1016/j.jcou.2016.11.011 Omega 3 Lipase Ethanolysis Supercritical carbon dioxide Supercritical carbon dioxide as solvent in the lipase-catalyzed ethanolysis of fish oil: kinetic study