Abstract
Immobilized lipase from Mucor miehei (Lipozyme IM-20) was employed in the esterification of butyric acid and isoamyl alcohol to synthesize isoamyl butyrate in n-hexane. Response surface methodology based on five-level, five-variable central composite rotatable design was used to evaluate the effects of important variables—enzyme/substrate (E/S) ratio (5–25 g/mol), acid concentration (0.2–1.0 M), alcohol concentration (0.25–1.25 M), incubation period (12–60 h), and temperature (30–50°C)—on esterification yield of isoamyl butyrate. In the range of parameters studied, the extent of esterification decreased with temperature, lower E/S ratios, and incubation periods. Excess acid and alcohol concentrations (i.e., acid/alcohol >1.4 or alcohol/acid >1.4) were found to decrease yield probably owing to inhibition of the enzyme by acid or alcohol, the former being more severe. The optimal conditions achieved are as follows: E/S ratio, 17 g/mol; acid concentration, 1.0 M; incubation period, 60 h; alcohol concentration, 1.25 M; and temperature, 30°C. With these conditions, the predicted value was 1.0 M ester, and the actual experimental value was 0.98 M.
Similar content being viewed by others
References
Armstrong, D.W., Selective Production of Ethyl Acetate by Candida utilis, in Biogeneration of Aromas, edited by T.H. Parliament and R. Croteau, ACS Symp. Ser. 317:254–265 (1986).
Langrand, G., C. Triantaphylides, and J. Baratti, Lipase Catalyzed Formation of Flavor Esters, Biotechnol. Lett. 10:549–554 (1988).
Langrand, G., N. Rondot, C. Triantaphylides, and J. Baratti, Short-Chain Flavor Esters Synthesis by Microbial Lipases, Ibid.:581–586 (1990).
Welsh, F.W., R.E. Williams, and K.H. Dawson, Lipase-Mediated Synthesis of Low Molecular Weight Flavor Esters, J. Food Sci. 55:1679–1682 (1990).
Cochran, W.G., and G.M. Cox, in Experimental Designs, 2nd edn., Wiley, New York, 1992, pp. 335–375.
Shieh, C.J., C.C. Akoh, and P.E. Koehler, Four-Factor Response Surface Optimization of the Enzymatic Modification of Triolein to Structured Lipids, J. Am. Oil Chem. Soc. 72:619–623 (1995).
Shieh, C.J., C.C. Akoh, and L.N. Yee, Optimized Enzymatic Synthesis of Geranyl Butyrate with Lipase AY from Candida rugosa. Biotechnol. Bioeng. 51:371–374 (1996).
Chulalaksananukul, W., J.S. Condoret, and D. Combes, Kinetics of Geranyl Acetate Synthesis by Lipase Catalyzed Transesterification in n-Hexane, Enzyme Microb. Technol. 14:293–298 (1992).
Chulalaksananukul, W., J.S. Condoret, and D. Combes, Geranyl Acetate Synthesis by Lipase Catalyzed Transesterification in Supercritical CO2, Ibid.:691–698 (1993).
Author information
Authors and Affiliations
Corresponding author
About this article
Cite this article
Krishna, S.H., Manohar, B., Divakar, S. et al. Lipase-catalyzed synthesis of isoamyl butyrate: Optimization by response surface methodology. J Amer Oil Chem Soc 76, 1483–1488 (1999). https://doi.org/10.1007/s11746-999-0189-x
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s11746-999-0189-x