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Isoamyl butyrate (banana flavor) was synthesized by esterification reaction of isoamyl alcohol and butyric acid in heptane medium. Immobilized Thermomyces lanuginosus lipase (TLL) prepared via physical adsorption on mesoporous poly-methacrylate particles (PMA) was used as biocatalyst. The factors that affect the esterification reaction were optimized by response surface methodology (RSM). Under optimal experimental conditions, maximum ester conversion percentage of 96.1 and 73.6% was reached after 50 and 90 min, respectively, for esterification reaction performed at equimolar ratio alcohol:acid at 500 and 2000 mM of each substrate. Under these experimental conditions, the esterification reaction was not controlled by external and intra-particle mass transfer effects. The product (isoamyl butyrate) was confirmed by proton nuclear magnetic resonance ((1)H NMR) spectroscopy. Reusability tests showed that the biocatalyst retained around 96 and 31% of its initial activity after eight successive esterification cycles performed at 500 and 2000 mM, respectively. The application of the biocatalyst prepared showed to be a promising strategy to catalyze flavor ester synthesis in a non-aqueous medium.

RESUMO -Lipase deThermomyces lanuginosus (LTL) foi imobilizada em partículas de poli-hidroxibutirato (PHB) para a preparação de biocatalisadores ativos. Neste estudo, foram oferecidos carregamentos de proteína de 0,5 a 100 mg/g de suporte. A adsorção da enzima seguiu o modelo de Langmuir (R 2 =0,9704). Máxima atividade hidrolítica de 1300 UI/g de suporte e concentração de proteína imobilizada de 26,5 ± 1,80 mg/g foi alcançada.A imobilização da enzima realizada com carregamentos de proteína inferior a 3 mg exibiu hiperativação (atividade recuperada acima de 100%). A enzima livre mostrou máxima atividade hidrolítica em pH 8,0 e 60°C, enquanto que o biocatalisador preparado a pH 7,5 e 65°C. A imobilização aumentou ligeiramente a estabilidade térmica da enzima no intervalo de temperatura entre 30 e 50°C, confirmado por determinação dos parâmetros termodinâmicos energia livre de Gibbs (ΔG 0 ), entalpia (ΔH 0 ) e entropia (ΔS 0 ).