CHAPTER 4: Commercial CLA and its Chemical Use

Upon conjugation of the carbon–carbon double bonds in linoleic acid, many interesting and useful properties arise. The collection of positional and geometric isomers of linoleic acid with conjugated carbon–carbon double bonds is denoted by the term conjugated linoleic acid (CLA). This chapter discusses the commercial preparation and chemical uses of CLA and conjugated vegetable oils. CLA is most commonly produced through base catalysed processes. Alternatively, CLA can be produced by dehydration of ricinoleic acid. Conjugated vegetable oils are nowadays produced by enzymatic esterification of CLA with glycerol. Nevertheless several processes are under investigation, allowing the one step production of conjugated vegetable oils, starting from vegetable oils, rich in linoleic acid. The most interesting options for the production of conjugated vegetable oils are the use of metal catalysts or via photo-irradiation. Although a lot of attention was given to the health benefits associated to a CLA-rich diet, only limited literature is available on the chemical use of CLA and conjugated vegetable oils. Nevertheless, in this chapter it will be illustrated that CLA and conjugated vegetable oils show great potential as renewable feedstocks in the chemical industry. CLAs and conjugated vegetable oils are, for instance, used in coating and inks as a drying oil. Moreover, conjugated fatty acids and oils are very reactive in Diels–Alder reactions, making them suitable to produce malenized fatty acids and triglycerides, which can be used as plasticizers. Finally, recent research illustrates their value in bio-based polymers and composites.