Synthesis Of Flavor Esters Catalyzed By Alkaline Lipase In Organic Solvent

The alkaline lipase from Penicillium expansum characteristics research indicated that the best enzymatic reaction temperature was40℃; the optimum pH of enzymatic reaction was8.5. Olive oil were used as the substrate and the enzymatic reaction fit the Michealis equation, the maximum reaction initial velocity Vm was16.70μmol/mL/min, Michaelis constant (Km) was35.4μmol/mL. The activation energy(Ea) was30.78kJ/mol.The kinetics of the esterification reaction catalyzed by Novozym435lipase was studied in organic solvents. When the concentration of ethyl caprylate is0.20mol/L, the initial rate V0increased. The initial rate also increase in in lipophilic solvents. The activation energy was17.58kJ/mol.The others research is focused on esterification catalyzed by an alkaline lipase as catalyst. The influence of some factors such as different kinds of organic solvent, mole ratio between acid and ethanol, quantity of enzyme, temperature of reaction, and reaction time was studied.Experiment conditions of Ethyl valerate:the organic solvent is n-octane, the concentration of ethyl valerate is0.20mol/L, the mole ratio between valeric acid and ethanol is1:1.5,certain amout of moecular sieve3A were added at the certain times. The result showed that, optimum reaction temperature36℃; optimum amount of alkaline lipase added:0.45g/bottle; the optimum esterification ratio was98%after24hours.Experiment conditions of Ethyl heptylate:the organic solvent is n-heptane, the concentration of ethyl valerate is0.20mol/L, the mole ratio between heptylic acid and ethanol is1:1.6. The result showed that optimum reaction temperature:36℃;optimum amount of alkaline lipase added:0.5g/bottle; the optimum esterification ratio was97%after24hours.Experiment conditions of Ethyl caprylate:the organic solvent is n-octane, the concentration of ethyl valerate is0.20mol/L, the mole ratio between Hexylacetic acid and ethanol is1:1.6. The result showed that,optimum reaction temperature:36℃; optimum amount of alkaline lipase added:0.50g/bottle; the optimum esterification ratio was97.6%after24hours.