Continuous preparation of flavour-active acetate esters by direct biocatalytic esterification

Mycelium-bound lipase(s) from Aspergillus oryzae catalysed direct esterification of isoamyl alcohol and cinnamyl alcohol with acetic acid in organic solvent, showing high stability towards substrates and products. Water produced during the esterification did not significantly affect the equilibrium of the reaction, allowing for high conversions. These features were exploited for preparing flavour-active acetate esters (isoamyl and cinnamyl acetate) in batch and continuous systems. A continuous stirred tank membrane reactor (CST-MR) was developed securing good reactor productivity and high biocatalyst stability.