Enhancement in synthesis of citronellyl laurate flavour by combined effect of ultrasound and immobilized lipase as heterogeneous biocatalyst

Abstract

This study aims to improve the performance of heterogeneous biocatalysts by using the combination of immobilized and ultrasonic lipases in the esterification reaction for the synthesis of citronellyl lauric flavors. Synthesis was conducted out through the reaction of citronellol with lauric acid by using immobilized lipase and ultrasonic. The results showed that immobilized lipase provided stability for up to 9 weeks and could be reused for 5 cycles of reactions. Immobilized lipase 473 U / gram was applied to the synthesis of citronellyl laurate with a reaction time of 90 minutes, 45⁰C, with and without ultrasonic. The result of citronellol conversion with ultrasonic is 3.6 x higher than conventional methode. It shows that the immobilization method provided stability to the biocatalyst, but because it had a limited internal mass transfer so the rate of reaction of ester formation reduced. On the other hand, ultrasonic contributed to increase the dispersion and collision of substrate molecules, reducing reaction time, and intensifying catalytic processes. Thus, the combination of immobilized enzyme and ultrasonic methods can be applied to biochemical processes widely.