Erucic acid is a natural product and chemical compound, a very long-chain monounsaturated omega-9 docosenoic fatty acid with a 22-carbon atom backbone. Its name is derived from the plant from which it was first obtained, Eruca sativa, belonging to the Brassicaceae family and known as rocket.
In nature, it is found as a component of larger molecules:
- Triglycerides. This is the most common form in which erucic acid appears: as part of triglycerides. Triglycerides are the main constituents of body fat in humans and animals, as well as vegetable fat. They are also present in the blood to enable the bidirectional transfer of adipose fat and glucose from the liver. It is one of the three fatty acids attached to the glycerol molecule in a triglyceride.
- Phospholipids. Erucic acid can also be a component of phospholipids, a class of lipids that is a major component of all cell membranes.
Erucic acid is usually obtained from natural sources such as rapeseed oil and the process takes place in different steps:
- Extraction. The oil is extracted from the seeds using a solvent such as hexane. The solvent dissolves the oil and is then evaporated, leaving behind the crude oil.
- Transesterification. Crude oil undergoes a process called transesterification, which involves a reaction with an alcohol, which can be methanol, in the presence of a catalyst. This process converts the triglycerides in the oil into glycerol and fatty acid esters.
- Separation. Fatty acid esters are at this important stage separated from glycerol and other components by methods such as distillation or chromatography.
- Hydrolysis. Fatty acid esters are hydrolysed by a reaction with water to break the ester bond. This produces the free fatty acids, including erucic acid, and alcohol.
- Purification. The erucic acid is purified, which may involve further distillation or other purification methods.
This is a simplified version but some processes may use enzymes or other methods to help with the extraction and separation of erucic acid.
Eruvic acid in its pure form appears as a colourless to pale yellow liquid. The colour may vary depending on specific conditions and purity. If erucic acid is mixed with other substances or has been exposed to air or light, it may take on a darker colour.
What it is used for and where
Cosmetics
Skin conditioning agent. It is the mainstay of topical skin treatment as it has the function of restoring, increasing or improving skin tolerance to external factors, including melanocyte tolerance. The most important function of the conditioning agent is to prevent skin dehydration, but the subject is rather complex and involves emollients and humectants that can be added in the formulation.
Pharmaceuticals
Erucic acid is used in some pharmaceutical applications, such as in the production of erucamide, a sliding agent used in polyolefin films.
Chemical industry
It is used to produce surfactants and emulsifiers, substances that help mix oil and water. These substances are used in a variety of products, including detergents, paints, etc.
Other uses
- Plasticisers. Erucic acid can be used as a plasticiser in the production of certain types of plastics, helping to increase their flexibility and durability.
- Biofuel. Certain types of biofuels, particularly biodiesel, can be produced using erucic acid.
- Lubricants. Erucic acid is used in the production of high-temperature or high-pressure lubricants due to its excellent lubricity and thermal stability.
- Nylon. Erucic acid is used in the production of certain types of nylon, a type of synthetic polymer.
Safety
Erucic acid is an acid that can cause toxicity in high doses on heart muscle function. However, since 1991, the European Community has established more restrictive cultivation lines for rapeseed, so the amount of this acid in rapeseed oil has drastically decreased. In 2016, EFSA proposed a lower maximum erucic acid content in edible oils of 2% (instead of 5%) and also suggested a tolerable daily intake of 7 mg erucic acid per kg body weight (1). It appears that these limits are generally respected in the European Union (2) both in oil and in fish products such as salmon and mackerel (3). However, warning should be given about the cumulative intake of this chemical compound.
- Molecular Formula C22H42O2
- Molecular Weight 338,6 g/mol
- CAS 112-86-7
- UNII
- EC Number 204-011-3
References_____________________________________________________________________
(1) Vetter, W., Darwisch, V., & Lehnert, K. (2020). Erucic acid in Brassicaceae and salmon–An evaluation of the new proposed limits of erucic acid in food. NFS journal, 19, 9-15.
Abstract. Erucic acid is a long-chain fatty acid classified as a natural toxin due to detrimental effects on heart muscle functions. Major sources of dietary intake of erucic acid are oil of rapeseeds and other Brassicaceae (formerly Cruciferae) such as mustard. In 2016, the European Food Safety Authority (EFSA) proposed a lower maximum content of erucic acid in edible oils of 2% (instead of 5%) and also suggested a tolerable daily intake of 7 mg erucic acid per kg body weight. In this article, we measured exemplarily samples of rapeseed, mustard, further Brassicaceae and used the data to discuss possible consequences for consumers, producers and the food sector. This data was supplemented with possible analytical problems caused the EFSA proposal and analysis of salmon fillet (erucic acid content: wild catch ~ farmed salmon < organic salmon) which, together with other fish, was verified as a relevant but unregulated source of erucic acid intake. Salmon also contained an isomer of erucic acid whose content was even higher than erucic acid.
(2) Russo, M., Yan, F., Stier, A., Klasen, L., & Honermeier, B. (2021). Erucic acid concentration of rapeseed (Brassica napus L.) oils on the German food retail market. Food science & nutrition, 9(7), 3664-3672.
Abstract. Rapeseed oil is one of the most important vegetable oils in Germany. It has a favorable fatty acid composition but also contains a certain amount of erucic acid (EA). As the result of toxicological considerations regarding this fatty acid, the European Food Safety Authority (EFSA) established a tolerable daily intake (TDI) for EA of 7 mg/kg body weight in 2016. On this basis, the maximum EA levels for vegetable oils allowed in the European Union have been reduced shortly from 50 to 20 g/kg, and for infant formula and follow-on formula from 10 to 4 g/kg. However, rapeseed oil is also recommended for the preparation of homemade food for infants and children. Little is known about the actual EA concentrations of rapeseed oils on the German retail market. Current data are especially important for the necessary reassessment of its recommendation in infant and child nutrition based on the established TDI. Three hundred representative rapeseed oil samples were purchased in retail stores across Germany. EA concentrations, determined by GC-FID, were in a range of 0.17–9.68 g/kg, with 241 samples being even below 4 g/kg. All oils were below the maximum level valid at the time of this investigation, and even below the newly established lower maximum level of 20 g/kg. The major part also met the requirements for infant and follow-on formula. The representative results provide valuable current data for the necessary reassessment of the dietary recommendations for infant and child nutrition based on the established TDI.
(3) Sissener, N. H., Ørnsrud, R., Sanden, M., Frøyland, L., Remø, S., & Lundebye, A. K. (2018). Erucic acid (22: 1n-9) in fish feed, farmed, and wild fish and seafood products. Nutrients, 10(10), 1443.
Abstract. The European Food Safety Authority (EFSA) published a risk assessment of erucic acid (22:1n-9) in 2016, establishing a Tolerable Daily Intake (TDI) for humans of 7 mg kg−1 body weight per day. This report largely excluded the contribution of erucic acid from fish and seafood, due to this fatty acid often not being reported separately in seafood. The Institute of Marine Research (IMR) in Norway analyzes erucic acid and has accumulated extensive data from analyses of fish feeds, farmed and wild fish, and seafood products. Our data show that rapeseed oil (low erucic acid varieties) and fish oil are the main sources of erucic acid in feed for farmed fish. Erucic acid content increases with total fat content, both in farmed and wild fish, and it is particularly high in fish liver, fish oil, and oily fish, such as mackerel. We show that the current TDI could be exceeded with a 200 g meal of mackerel, as at the maximum concentration analyzed, such a meal would contribute 143% to the TDI of a 60 kg person. These data cover a current knowledge gap in the scientific literature regarding the content of erucic acid in fish and seafood.
Erucic acid 
