Enzymatic production of mono- and diglycerides in compressed n-butane and AOT surfactant

This work reports the production of mono- and diglycerides from olive oil in pressurized n-butane as solvent medium. For this purpose, a commercial immobilized lipase (Novozym 435) was employed as a catalyst and sodium (bis-2-ethyl-hexyl) sulfosuccinate (Aerosol-OT or AOT) as a surfactant. The experiments were conducted in the batch mode varying the glycerol-to-oil molar ratio, n-butane-to-substrate mass ratio, enzyme concentration, temperature, pressure, and AOT concentration. Results showed that lipase-catalyzed glycerolysis in compressed n-butane might be a potential alternative route to conventional methods, as high contents of reaction products, especially monoglycerides (∼70 wt%), were achieved at mild temperature and pressure with a relatively low solvent-to-substrate mass ratio (4:1) in short reaction times (2 h).