Unusual Fatty Acids from Plant Seed Oils

Innovations in pharmaceuticals, functional foods, cosmetics, crop protection agents, adjuvants and other formulants could all potentially come from unusual fatty acids which are currently generally unknown or undervalued. These are present in the seed oils of plants with the potential to develop as niche crops in the UK. This is a brief overview of some of the potential for unusual fatty acids already reported in academic and patent literature.

Major oilseeds and their common fatty acids
Oily seeds from crops such as soybeans, sunflower, cotton, oil palm and rapeseed are major world food and animal feed commodities, and their oils have also become feedstocks for biodiesel and various biomaterials. Oils of these species contain fatty acid molecules with predominantly 16 or 18 carbon atom chains and zero, one or two double bonds, eg palmitic, stearic, oleic, and linoleic acids. Other common fatty acids include lauric and myristic acids, with 12 and 14 carbon atom chains, respectively, usually sourced from coconuts.

Properties and applications of unusual fatty acids
In Europe, new niche oilseed crops have been introduced from time to time, eg borage and evening primrose for their oils rich in gamma linolenic acid in the 1980s. Health and nutritional benefits have been ascribed to GLA.  More recently, crambe has been developed for its oil rich in erucic acid; and there has been interest in marigold seed oil for calendic acid. Erucic acid is useful as a lubricant and paint additive. Calendic acid has three conjugated double bonds and is useful in the manufacture of paints and coatings because it 'dries' (oxidises) quickly on exposure to air.

Many other fatty acids have been identified in plant seed oils. In addition to often longer carbon chains, these potentially undervalued fatty acids include those with double bonds in various positions and the presence of functional groups. Good examples of such exotic fatty acids are the long chain nervonic acid and the more chemically complex dimorphecolic acid.