Effect of several reaction parameters in the solvent-free ethyl oleate synthesis using Candida rugosa lipase immobilized on polypropylene

MARÍA LAURA FORESTI; ALBERTO ERRAZU; MARÍA LUJÁN FERREIRA

BIOCHEMICAL ENGINEERING JOURNAL

Año: 2005 vol. 25 p. 69 - 77

1369-703X

The effect of several reaction parameters on the yield of ethyl oleate using free and immobilized Candida rugosa lipase (CRL) has been studied. Reaction was performed in absence of solvents. The dependence of enzymatic activity on ethanol molar concentration, initial water content, acidity of the aqueous media added, mass of catalyst, reaction temperature, substrate ratio, etc., has been addressed. Specific enzymatic activities achieved using the immobilised lipase were compared with the ones obtained using free lipase in similar conditions. Best results were achieved using 50-150 mg of immobilized lipase on polypropylene (PP), 3 g oleic acid, 0.5 g ethanol and 0.6 g buffer of pH 7 (20 % of the oleic acid mass), at 45° C and 350 rpm. Kinetic studies were also performed. Both, ethanol and butanol demonstrated to have a strong inhibiting effect on the lipase and after 30 minutes of reaction no further conversion was found. Agglomeration of lipase free and immobiliized was also detected and discussed considering published literature.