Flavour and fragrance compounds are widely used additives in e.g. nutrition industry. Extraction of those compounds from plant materials is expensive and is often limited by the availability of the natural sources.

Esters of short chain fatty acids and alcohols are a large group of flavours. They can be obtained by enzymatic synthesis carried out in non-aqueous organic solvents [1]. The application of lipases to synthesize esters has been reported in many publications [2,3].

In the present communication, the effects of important reaction parameters on the lipase-catalyzed synthesis of 1-butyl caproate and isoamyl acetate were investigated. A free and immobilized lipase from Basidiomycete Bjerkandera adusta R59 were employed.

Enzymatic synthesis of 1-butyl caproate at 45^oC under shaking (150 rpm) was performed for 72 h in cyclohexane. The highest conversion rate (93 % and 97 %, respectively) was observed with 360 U of free Bjerkandera adusta lipase and with 70 U of immobilized lipase. The substrate molar ratio caprylic acid: butanol was of 2:3 (at 0.2 M acid concentration). In the case of isoamyl acetate, the optimum conditions, giving 44 % of conversion after 72 h, were obtained with 70 U of immobilized lipase, a molar ratio acetic acid to isoamyl alcohol of 2:3 and at 50^oC. The esterification reactions of isoamyl acetate were carried out in cyclohexane and the initial substrate concentrations were 0.2 M each. Immobilized lipase could be repeatedly used for four cycles without a decrease of synthesis activity.

1. Dordick J.S. (1989). Enzymatic catalysis in monophasic organic solvents. Enzyme Microb. Technol. 41: 566 – 571.

2. Abbas H., Comeau L. (2003). Aroma synthesis by immobilized lipase from Mucor sp. Enzyme Microb. Technol. 32: 589 – 595.

3. Karra-Chaabouni M., Ghamgui H., Bezzine S., Rekik A., Gargouri Y. (2006). Production of flavour esters by immobilized Staphylococcus simulans lipase in a solvent-free system. Process Biochem. 41: 1692 – 1698.

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