Lipase-catalyzed synthesis of isoamyl acetate in free-solvent media- optimization using a central composite design

The catalytic action of two non commercial lipases (E.C. 3.1.1.3) in the synthesis of isoamyl acetate in a solvent-free system, were tested using an experimental design in order to better understand the relationship between the reaction variables. Yields ranging from 67 to 77 % molar conversion were achieved. The synthesis of isoamyl acetate catalyzed by the chosen lipase (Rhizopus sp.) was optimized, in order to maximize the molar conversion (yield, Y) in a solvent-free system. Response surface methodology involving the substrate molar ratio (RM) and amount of lipase (L) was used, and a second order model was employed to generate response surfaces. The optimum conditions to obtain Y max = 80% were: RM = (2:1); L = 8.7% (w/w), 40 degrees C, and 48 hours of reaction time.