THE CONFERENCE PROCEEDINGS - IFEAT

Bioconversion of coconut oil to esters –using fusel alcohols and lipaseBioconversion of coconut cream to esters –using 2-phenylethanol and lipases3503002-Phenylethyl octanoate(GC-FID Peak Area x 10 6 )2502001501005000 5 10 15 20 25 30Incubation Time (h)BIOCONVERSION OF COCONUT OIL AND PALM KERNEL OIL TO AROMA-ACTIVEMETHYL KETONESIn addition to esters, the fatty acids in coconutoil and palm kernel oil can be converted intomethyl ketones by fungal fermentation. Methylketones impart “fruity” odours and constitute thecharacter-impact aroma compounds in bluecheeses, the so-called “blue flavour”. Thesecompounds have flavour and fragranceapplications, even as insecticides, insectrepellents or animal repellents. Bioconversion ofC8-C14 fatty acids to methyl ketones by fungalfermentation results in the production of 2-heptanone (C7), 2-nonanone (C9), 2-undecanone (C11) and 2-tridecanone (C13) with2-undecanone being the dominant volatile due tothe abundance of lauric acid. This biotransformation process offers a great potential to build a libraryof natural methyl ketones from the biomaterials, coconut oil and palm kernel oil.COMMERCIAL AND PRACTICAL CONSIDERATIONSBioconversion of coconut oil and palmkernel oil to aroma-active methyl ketones• Methyl ketones – fruity, blue cheese aroma• Flavour and fragrance applications, even asinsecticide, insect repellent or animal repellent• Bioconversion of C8-C14 fatty acids to methylketones by fungal fermentation – 2-heptanone, 2-nonanone, 2-undecanone, 2-tridecanone• Potential to build a library of natural methyl ketonesThe commercial aspects of the bioprocess andproduction of bioesters from coconut and palmkernel oils depend on several factors such as costof oil, prices of natural and synthetic esters, scaleof operation and yield of esters. The yield ofoctanoate esters was about 7% (g/100 g coconutoil). The yield of laurate esters could be higherdue to the higher laurate content in the oils. Theprice of coconut and palm kernel oils is currentlyaround US$1000 per metric ton (Sept 2012).Information on natural and synthetic laurateesters is not available. A number of lipases canCommercial, practical considerations• Scale up – from current lab scale of 100 mL or less to 10L, 100 L and higher volumes• Yields – 7% (g/100 g oil) based on octanoate esters,may be higher for laurate esters• Cost of coconut oil and palm kernel oil – currently aroundUS$1000 per metric ton (Sept 2012)• Other economic aspects – prices of natural vs. syntheticesters (information not accessible)• Enzymes (lipases) – Palatase and LIPOZYMEs (TL IM,IM RM, Novozym435 etc)• Product recovery – not studied yet, distillation andmembrane separation (possible options)191