Castor oil is unique in that it is a triacylglycerol (TAG) oil in which nearly 90% of the fatty acids are the unusual fatty acid, Ricinoleic acid (18:1-OH).

Hydroxy fatty acids are only rarely found in the plant kingdom. A small number of species are known to produce ricinoleic acid but none make an oil of the incredible acyl purity of castor oil.

Biochemical studies have revealed that ricinoleic acid is produced in castor by the direct hydroxylation of the common fatty acid, oleic acid (18:1).

The hydroxylation reaction is catalysed by a single, highly efficient enzyme, the fatty acid hydroxylase.

This enzyme has been cloned and expressed in genetically engineered plants to produce novel seed oils containing ricinoleic acid.

Linnaeus has exclusive rights to this enzyme and the utilization of fatty acid hydroxylases in transgenic plants to produce seed oils containing hydroxy fatty acids.