Erucic acid


Erucic acid is a monounsaturated omega-9 fatty acid, denoted 22:1ω9. It has the chemical formula:. It is prevalent in wallflower seed and other plants in the family Brassicaceae, with a reported content of 20 to 54% in high erucic acid rapeseed oil and 42% in mustard oil. Erucic acid is also known as cis-13-docosenoic acid and the trans isomer is known as brassidic acid. Cetoleic acid is a positional isomer of erucic acid.

Uses

Erucic acid is a precursor to brassylic acid, a C13-dicarboxylic acid that is used to make specialty polyamides and polyesters. The conversion entails ozonolysis, which selectively cleaves the C=C bond in erucic acid:
Amides of erucic acid are used as lubricants and surfactants.
Hydrogenation of erucic acid gives behenyl alcohol,, a pour point depressant, and which can be made into silver behenate, for use in photography.

Biochemistry

Erucic acid is produced by elongation of oleic acid via oleoyl-coenzyme A and malonyl-CoA. Erucic acid is broken down into shorter-chain fatty acids in the human liver by the long-chain acyl CoA dehydrogenase enzyme.

Health effects

As early as 1977, the use of rapeseed oil was deemed safe as a food additive in the United States.
In 2003, Food Standards Australia set a provisional tolerable daily intake for an average adult of about 500 mg/day of erucic acid, extrapolated based on "the level that is associated with increased myocardial lipidosis in nursing pigs." "There is a 120-fold safety margin between this level and the level that is associated with increased myocardial lipidosis in nursing pigs. The dietary exposure assessment has concluded that the majority of exposure to erucic acid by the general population would come from the consumption of colza oil. The dietary intake of erucic acid by an individual consuming at the average level is well below the PTDI; therefore, there is no cause for concern in terms of public health and safety. However, the individual consuming at a high level has the potential to approach the PTDI. This would be particularly so if the level of erucic acid in colza oil were to exceed 2% of the total fatty acids."
Food-grade rapeseed oil is regulated to a maximum of 2% erucic acid by weight in the US and Europe.