The production of polyunsaturated fatty acids (PUFAs) concentrates by enzymatic catalysis has
gained interest due to their stereospecificity and the milder conditions employed compared to the
use of inorganic catalysts. The enzymatic glycerolysis of sardine oil by Lipozyme 435 to get PUFA
concentrates in the forms of di‐ and monoacylglycerols (DAGs, MAGs) in an optimized amount of
tert‐butanol as the organic solvent was studied. First, mass transfer limitation of the reaction system
was analyzed. The effects of different operating variables such as lipase loading, temperature
and feed composition were investigated. A semi‐empirical kinetic model based on the reversible
elementary reactions of glycerolysis and hydrolysis of the glycerides was employed to correlate the
experimental kinetic data. A molar ratio glycerol:oil of 3:1 was the optimum, which produced more
than 84 wt% of MAG at 323 K. A comparison with other glycerolysis systems was performed using
MAG yield, reaction rate and significance of kinetic parameters.
