Isoamylacetate production by entrapped and covalently bound Candida rugosa and porcine pancreatic lipases

Candida rugosa lipase (CRL) and porcine pancreatic lipase (PPL) were immobilised by entrapping and also by covalent binding for use in synthesis of isoamyl acetate (IAAc), which has a typical banana flavour. Lipase entrapment was carried out by dripping sodium alginate (Na-Alg)-chitosan (Chi)-lipase mixture into CaCl2-glutaraldehyde (GAL) solution to obtain Ca-Alg/ChiCRL/PPL. Immobilisation conditions were optimised as 1.5% Na-Alg, 1.5% chitosan and 0.15% GAL. Ca-Alg/ChiCRL/PPL samples showed the highest activity when they were dried upon reaching 27% of their initial weights. Covalent binding was achived with Chi modified with spacerarm via glutaraldehyde to get ChiCRL/PPL. The highest IAAc production was observed when 1,3-diaminopropane was used as a spacer arm. The best ester yield was achieved in heptane, at 40 and 45 °C reaction temperatures, 50 mM IAA and 50 or 75 mM AA concentrations. The amount of IAAc was nearly 10 times higher for the batch type than for the continuous packed bed column reactor.