ACETYLACYLGLYCEROL FORMATION BY LIPASE IN MICROAQUEOUS MILIEU - EFFECTS OF ACETYL GROUP DONOR AND ENVIRONMENTAL-FACTORS

Of six lipases evaluated, lipozyme was most efficacious at mediating a cyl-exchange reactions in forming acetylacylglycerols (AcAG) from acet yl donors and olive oil triacylglycerols (TAG) in the absence of organ ic solvent. Reactivity among a series of 10 acetyl-donor substrates wa s compared for model reactions configured for acetyl transfer to 1-und ecanol and ac(et)yl exchange with olive oil. Of the two acetyl donors most suitable for exchange reactions with olive oil, triacetin was a m ore efficient cosubstrate than was ethyl acetate. Greatest absolute yi elds of total AcAG were observed at molar ratios of triacetin/olive oi l TAG of 1:2 and ethyl acetate/olive oil TAG of about 3:1, and respect ive reaction yields approached 90% and 50% of the calculated maximum f or these two systems. AcAG formation was optimal at about 1-2% total w ater content in the system and at 80-85 degrees C. When organic solven ts were used as an inert dispersing medium, those of intermediate pola rity were most supportive of biocatalysis.