Sintese enzimatica dos esteres de aroma butirato e valerato de citronelila por lipase de Rhizopus sp. / Enzymatic synthesis of the butyric flavor esters and valeric citronellyl by lipase of Rhizopus sp.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

The enzymatic synthesis of citronellyl flavor esters with a non commercial lipase from Rhizopus sp was investigated. The results were compared with other lipases from Fusarium 152 B, Fusarium 160 A1, Tricoderma sp, and Alcaligenes sp. The lipase from Rhizopus sp was selected as better biocatalyst for the citronelyl ester synthesis. It was verified the effect of the acyl donor chain length as well as the use of organic solvent on the esterification rate. The ester production was higher for butyric and valeric acids. The same yield was observed in organic solvent (isooctane) and in solvent-free systems. A two level fatorial design was used to optimize the ester synthesis. The reaction parameters were substrate molar ratio (alcohol/acid) and enzyme amount (% for mass of reactants). This study showed that the lipase has the best catalytic activities with molar ratio 2,41:1 and enzyme amount, 6%. The behavior of the immobilized lipase on celite was studied and its esterification activity improved, mainly under the best operational conditions. However, immobilized lipase on celite is not appropriate with respect to reuse because its activity decreased after few cycles. During the study it was observed that the lipase has no enantioselectivity in the synthesis of citronellyl flavor esters.

ASSUNTO(S)

esteres lipases enzimas - sintese rhizopus esters enzymes lipase

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