Production of geranyl propionate by enzymatic esterification of geraniol and propionic acid in solvent-free system

ACKGROUND: This work reports the optimization of geranyl propionate production by esterification of geraniol and propionic acid in a solvent-free system using a commercial lipase as catalyst. For this purpose, a sequential strategy was performed applying two experimental designs. RESULTS: The operating conditions that optimized geranyl propionate production were determined to be 40 degrees C, geraniol to propionic acid molar ratio of 3 : 1, 150 rpm and 10 wt% of enzyme, with a resulting reaction conversion of about 93%. After determining the optimum reaction parameters, a kinetic study was carried out evaluating the influence of substrates molar ratio, enzyme concentration and temperature on reaction conversion. Results obtained in this step allow one to conclude that an excess of alcohol (acid to alcohol molar ratio of 1 : 6), relatively low enzyme concentration (5 wt%), temperature of 40 degrees C and substrates molar ratio of 1 : 1 afforded nearly complete reaction conversion after 30 min of reaction. CONCLUSION: New experimental data on enzymatic esterification of geraniol and propionic acid for geranyl propionate production are reported in this work, showing a promising perspective of the technique to over come the well-known drawbacks of the chemical-catalyzed route. (C) 2010 Society of Chemical Industry