Erucic acid
Template:Use dmy dates Template:Chembox Erucic acid is a monounsaturated omega-9 fatty acid, denoted 22:1ω9. It has the chemical formula: Template:Chem2. 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<ref>Template:Cite journal</ref> 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.<ref name=Ullmann/>
Hydrogenation of erucic acid gives behenyl alcohol, Template:Chem2, a pour point depressant (enabling liquids to flow at a lower temperature), and which can be made into silver behenate, for use in photography.<ref>Template:Cite journal</ref>
Sources of erucic acid
The name erucic means "of or pertaining to Eruca", which is a genus of flowering plants in the family Brassicaceae. The genus includes colewort (E. sativa), which today is better known as arugula (US) or rocket (UK).
Erucic acid is produced naturally (together with other fatty acids) across a great range of green plants, but especially so in members of the genus Brassica. For industrial purposes and production of erucic acid, rapeseed is used; for food purposes a 'low-erucic acid rapeseed' (LEAR) has been developed (canola), which contains fats derived from oleic acid instead of erucic acid.<ref name=Ullmann>Template:Cite book</ref>
Biochemistry
Template:Further Erucic acid is produced by elongation of oleic acid via oleoyl-coenzyme A and malonyl-CoA.<ref name=Bao>Template:Cite journal</ref> 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.<ref name=CFR21>U.S. Dept. of Health and Human Services, CFR – Code of Federal Regulations Title 21 1 April 2010.</ref>
In 2003, Food Standards Australia set a provisional tolerable daily intake (PTDI) 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."<ref name=fsa>Food Standards Australia New Zealand (June 2003) Erucic acid in food: A Toxicological Review and Risk Assessment Template:Webarchive Technical report series No. 21; Page 4 paragraph 1; Template:ISBN, ISSN 1448-3017</ref> "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 (rapeseed oil, but not from the cultivar developed to produce canola 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."<ref name=fsa />
Food-grade rapeseed oil (also known as canola oil, rapeseed 00 oil, low erucic acid rapeseed oil, LEAR oil, and rapeseed canola-equivalent oil) is regulated to a maximum of 2% erucic acid by weight in the US and Europe.<ref name=CFR21 /><ref>Template:Cite web</ref>