Jump to main content
Jump to site search

Issue 11, 2012
Previous Article Next Article

A clean enzymatic process for producing flavour esters by direct esterification in switchable ionic liquid/solid phases

Author affiliations

Abstract

A clean biocatalytic approach for producing flavour esters using switchable ionic liquid/solid phases as reaction/separation media has been developed. The phase behaviour of different IL/flavour acetyl ester (geranyl acetate, citronellyl acetate, neryl acetate and isoamyl acetate) mixtures was studied at several concentrations, resulting for all cases in fully homogeneous liquid media at 50 °C, and solid systems at room temperature. By using an iterative centrifugation protocol on the solid IL/flavour ester mixtures at controlled temperatures, the solid IL phase and the liquid flavour ester phase can be easily separated. The excellent suitability of an immobilized Candida antarctica lipase B (Novozym 435) catalyst in the esterification reaction between an aliphatic carboxylic acid (acetic, propionic, butyric or valeric) and a flavour alcohol (isoamyl alcohol, nerol, citronellol or geraniol) in N,N′,N′′,N′′′-hexadecyltrimethyl-ammonium bis(trifluoromethylsulfonyl)imide ([C16tma][NTf2])IL has been demonstrated, the product yield being improved up to 100% under appropriate reaction conditions (enzyme amount, dehydrating molecular sieves, etc.) at 50 °C. The enzymatic synthesis of sixteen different flavour esters was carried out in [C16tma][NTf2] by means of this approach, providing products of up to 0.757 g mL−1 concentration after IL separation. The residual activity of the enzyme/IL system during seven consecutive operation cycles was shown to be practically unchanged after reuse.

Graphical abstract: A clean enzymatic process for producing flavour esters by direct esterification in switchable ionic liquid/solid phases

Back to tab navigation

Supplementary files

Publication details

The article was received on 12 Jul 2012, accepted on 20 Aug 2012 and first published on 20 Aug 2012


Article type: Paper
DOI: 10.1039/C2GC36081K
Citation: Green Chem., 2012,14, 3026-3033
  •   Request permissions

    A clean enzymatic process for producing flavour esters by direct esterification in switchable ionic liquid/solid phases

    P. Lozano, J. M. Bernal and A. Navarro, Green Chem., 2012, 14, 3026
    DOI: 10.1039/C2GC36081K

Search articles by author

Spotlight

Advertisements