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
Brassicaceae () or (the older but equally valid) Cruciferae () is a medium-sized and economically important Family (biology), family of flowering plants commonly known as the mustards, the crucifers, or the cabbage family. Most are herbaceous pla ...
, with a reported content of 20 to 54% in high erucic acid
rapeseed oil
Close-up of canola blooms
Canola flower
Rapeseed oil is one of the oldest known vegetable oils. There are both edible and industrial forms produced from rapeseed, the seed of several cultivars of the plant family Brassicaceae. Historica ...
and 42% in
mustard oil
Mustard oil can mean either the pressed oil used for cooking or a pungent essential oil, also known as volatile oil, of the mustard plant. The essential oil results from grinding mustard seed, mixing the grounds with water, and isolating the resu ...
. 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
In organic chemistry, a dicarboxylic acid is an organic compound containing two carboxyl groups (). The general molecular formula for dicarboxylic acids can be written as , where R can be aliphatic or aromatic.Boy Cornils, Peter Lappe "Dicarbox ...
that is used to make specialty
polyamide
A polyamide is a polymer with repeating units linked by amide bonds.
Polyamides occur both naturally and artificially. Examples of naturally occurring polyamides are proteins, such as wool and silk. Artificially made polyamides can be made throug ...
s and
polyester
Polyester is a category of polymers that contain one or two ester linkages in every repeat unit of their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include some natura ...
s. The conversion entails
ozonolysis
In organic chemistry, ozonolysis is an organic reaction where the Saturated and unsaturated compounds, unsaturated bonds are Bond cleavage, cleaved with ozone (). Multiple carbon–carbon bond are replaced by carbonyl () groups, such as aldehydes ...
, which selectively cleaves the C=C bond in erucic acid:
CH
3(CH2)7CH\dCH(CH2)11CO2H + O3 + 0.5 O2 -> CH3(CH2)7CO2H + HO2C(CH2)11CO2H
Amide
In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a chemical compound, compound with the general formula , where R, R', and R″ represent any group, typically organyl functional group, groups or hydrogen at ...
s of erucic acid are used as lubricants and surfactants.
[
]Hydrogenation
Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to redox, reduce or Saturated ...
of erucic acid gives behenyl alcohol, , a pour point depressant (enabling liquids to flow at a lower temperature), and silver behenate, for use in photography.
Sources of erucic acid
The name ''erucic'' means "of or pertaining to '' Eruca''", which is a genus of flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...
s in the family Brassicaceae
Brassicaceae () or (the older but equally valid) Cruciferae () is a medium-sized and economically important Family (biology), family of flowering plants commonly known as the mustards, the crucifers, or the cabbage family. Most are herbaceous pla ...
. The genus includes colewort ('' E. sativa''), which today is better known as arugula
Rocket, eruca, or arugula (''Eruca sativa'') is an edible annual plant in the family Brassicaceae used as a leaf vegetable for its fresh, tart, bitter, and peppery flavor. Its other common names include salad rocket and garden rocketFlora of NW ...
(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
''Brassica'' () is a genus of plants in the cabbage and mustard family (Brassicaceae). The members of the genus are informally known as cruciferous vegetables, cabbages, mustard plants, or simply brassicas. Crops from this genus are sometim ...
''. For industrial purposes and production of erucic acid, rapeseed
Rapeseed (''Brassica napus'' subsp. ''napus''), also known as rape and oilseed rape and canola, is a bright-yellow flowering member of the family Brassicaceae (mustard or cabbage family), cultivated mainly for its oil-rich seed, which naturall ...
is used; for food purposes a 'low-erucic acid rapeseed' (LEAR) has been developed (canola
file:CanolaBlooms.JPG, Close-up of canola blooms
file:Canola Flower.jpg, Canola flower
Rapeseed oil is one of the oldest known vegetable oils. There are both Edible oil, edible and industrial forms produced from rapeseed, the seed of several ...
), which contains fats derived from oleic acid
Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish due to the presence of impurities. In chemical terms, oleic acid is cl ...
instead of erucic acid.
Biochemistry
Erucic acid is produced by elongation of oleic acid via oleoyl-coenzyme A
Coenzyme A (CoA, SHCoA, CoASH) is a coenzyme, notable for its role in the Fatty acid metabolism#Synthesis, synthesis and Fatty acid metabolism#.CE.B2-Oxidation, oxidation of fatty acids, and the oxidation of pyruvic acid, pyruvate in the citric ac ...
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
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
.
Health effects
As early as 1977, the use of rapeseed oil was deemed safe as a food additive
Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives, such as vinegar ( pickling), salt ( salting), smoke ( smoking) and sugar ( crystallization), have been used f ...
in the United States.[U.S. Dept. of Health and Human Services]
CFR – Code of Federal Regulations Title 21
1 April 2010.
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."[Food Standards Australia New Zealand (June 2003]
Erucic acid in food: A Toxicological Review and Risk Assessment
Technical report series No. 21; Page 4 paragraph 1; , ISSN 1448-3017 "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."
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.
References
External links
Erucic acid MS Spectrum
{{DEFAULTSORT:Erucic Acid
Fatty acids
Alkenoic acids