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Synthesis of eugenyl acetate by enzymatic reactions in supercritical carbon dioxide

Paper ID Volume ID Publish Year Pages File Format Full-Text
2668 126 2016 9 PDF Available
Title
Synthesis of eugenyl acetate by enzymatic reactions in supercritical carbon dioxide
Abstract

•Optimal condition for the synthesis of eugenyl acetate in SC-CO2 was determined at 60 °C/10 MPa.•The phase behavior of the reaction system and the synthesis in organic medium also were studied.•The conversion and yield of eugenyl acetate decreased with the increasing number of cycles.•The affinity of acetic anhydride to the enzyme was larger than that of eugenol.•The second step of the reaction kinetics required more energy that the first step.

Supercritical carbon dioxide (SC-CO2) as reaction medium has gained attention in the production of terpenic esters catalyzed by lipases. Therefore, this work investigated the production of eugenyl acetate by esterification of eugenol and acetic anhydride in SC-CO2 using two commercial lipases (Lipozyme 435 and Novozym 435) as catalysts. The influence of enzyme concentration (1–10% weight/weight), substrates’ molar ratio (1:1 to 5:1), temperature (40–60 °C) and pressure of SC-CO2 (10–30 MPa) on the esterification rate (X; %) and specific productivity (SP; kg of product/kg of catalyst x hour) were evaluated. A home-made high-pressure stirred-batch reactor (100 ml) was used in the experiments. The use of Novozym 435 achieved higher conversion and specific productivity of eugenyl acetate than Lipozyme 435. An excess of acetic anhydride (5:1 M/M) and high enzyme concentration (10%) achieved higher esterification rates than the lowest conditions (1% and 1:1 M/M). The optimal temperatures and pressure for the synthesis of eugenyl acetate in SC-CO2 were 50 and 60 °C at 10 MPa, respectively. The phase behavior of the reaction system and the synthesis in organic medium were also studied. Kinetic experiments performed at 40, 50 and 60 °C indicated that the reaction follows the simple Ping-Pong Bi-Bi mechanism and the affinity of acetic anhydride to enzyme was larger than that of eugenol.

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Keywords
Eugenol; Lipozyme 435; Novozym 435; Esterification; Supercritical
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Synthesis of eugenyl acetate by enzymatic reactions in supercritical carbon dioxide
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Publisher
Database: Elsevier - ScienceDirect
Journal: Biochemical Engineering Journal - Volume 114, 15 October 2016, Pages 1–9
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us