The efficiency of lipase catalyzed glycerolysis of sardine oil in solvent free and supercritical
carbon dioxide media has been investigated. The immiscibility between substrates, glycerol
and oil, is an important drawback to reach good high conversions of triglycerides (TAG) into
monoglycerides (MAG) and diglycerides (DAG) in short reaction times. To improve mass
transfer rates, emulsification of both reactants as reverse micelles (glycerol-in-oil) has been
carried out. Enzyme-catalyzed reaction is an attractive alternative since the reaction can be
carried out under mild conditions avoiding the oxidation of omega-3 fatty acids. In this work,
a commercial immobilized lipase (Lipozyme 435) was employed as biocatalyst. The effects of
SC-CO2 density on reaction rates and oxidation stability has been compared with those
obtained in solvent free system at atmospheric pressure. The effect of temperature and
pressure on reaction yield, oxidation state of reaction products and enzyme stability was
studied. Good stability of Lipozyme 435 has been observed in both systems proving no
thermal deactivation at temperatures higher than its optimum.
