Green synthesis routes toward triglycerides of conjugated linoleic acid

The classical chemical synthesis of CLA triglycerides starting from the free fatty acids and glycerol leads to the formation of additional CLA isomers not suited for applications in the field of human nutrition. Greener methods for a more selective production of CLA triglycerides under gentle reaction conditions were evaluated 1-4. The enzymatic synthesis works well under vacuum conditions with a clear preference for free fatty acids as substrates in comparison to alkyl esters. The reaction velocity was enhanced significantly by the addition of basic additives into the reaction mixture. A combined one pot synthesis was designed starting from ethyl esters consisting of an enzymatic ester hydrolysis followed by a re-synthesis of the fatty acids with glycerol. Additionally, a new chemical interesterification reaction with triacetin (triacetyl glyceride) as synthon was developed, which avoids the formation of undesired CLA isomers.