3-MCPD fatty acid ester

3-MCPD-fatty acid ester are esters of various fatty acids with 3-chloro-1,2-propanediol (3-MCPD, 3- M ono c hlor p ropan d iol), a chlorinated diol as the alcohol component . They are process-related contaminants in food which - especially for younger people - have a potential to be harmful to health and are therefore undesirable in food.

Occurrence

3-MCPD fatty acid esters can be found in all refined , i.e. purified, vegetable oils , the contents of which differ greatly in some cases.

The refining of fats and oils does not have to be marked on the products. If an edible vegetable oil is not labeled as either “native” or “cold-pressed”, it is most likely refined. Since animal fats, with the exception of fish oils, are generally not refined, no 3-MCPD esters have so far been detected in these fats.

Many foods that require purified vegetable fats for their production therefore also contain 3-MCPD fatty acid esters. High amounts of 3-MCPD esters were found in deep-frying fat and margarine in particular . Hardened fats in particular show high values after being refined a second time. But 3-MCPD fatty acid esters have also been detected in other foods such as nut nougat cream and baby food . Obviously, 3-MCPD fatty acid esters are part of the food chain . This is why this substance is now also found in breast milk .

The values found in food sometimes differ considerably from one another. Precise analysis methods are still being developed.

Emerge

When processing vegetable oils and fats at high temperatures, 3-MCPD fatty acid esters can be formed. The reaction component 3-chloro-1,2-propanediol is formed from glycerine , which can react with chloride to form 3-MCPD.

Schematic representation of the formation of a 2-MCPD fatty acid ester , a 3-MCPD fatty acid ester and a glycidyl fatty acid ester from a fat or oil:

So they are primarily formed during the necessary refining . The refining of vegetable fats is a multi-stage chemical and physical process through which the oils are made edible. This removes impurities such as undesirable mucilage, acids, dyes, oxidation products and smells and flavors, but also toxic substances such as pesticides , heavy metals , poisonous plant ingredients , mycotoxins and polycyclic aromatic hydrocarbons . The 3-MCPD fatty acid esters are formed particularly in the last step of the refining, deodorization by steam distillation at temperatures of up to 250 ° C.

Health importance

"Free" MCPD (3-chloro-1,2-propanediol)
3-MCPD without specifying the stereochemistry
( R ) -3-MCPD
( S ) -3-MCPD

In 2011, 3-MCPD was classified as a "possible human carcinogen" by the International Agency for Research on Cancer (IARC).

3-MCPD is mainly absorbed as 3-MCPD fatty acid ester from refined fats and oils and fatty foods. Studies on rats initiated by the Federal Institute for Risk Assessment (BfR) show that the amount of 3-MCPD that is absorbed after administration of 3-MCPD fatty acid ester differs only insignificantly from the amount absorbed after administration of “free” 3-MCPD . The BfR therefore bases the risk assessment on the complete splitting off of fatty acids from the 3-MCPD fatty acid esters supplied with food:

With reference to more recent scientific research results on the toxicology of 3-MCPD, the European Food Safety Authority has set a TDI of 0.8 µg / kg body weight. If the risk assessment is based on the case assumed by the BfR that the 3-MCPD fatty acid esters are completely converted into free, unesterified 3-chloro-1,2-propanediol during digestion, the 3-MCPD esters must be molar equivalent TDI can be assumed. In the opinion of the BfR, the possibly high exposure of infants who are not breastfed represents a particular problem. Particularly in the case of infants, the safety margin to the effects observed in animal experiments may be too small due to the consumption of starter and follow-on foods. According to the BfR, measurements in 2007 actually showed that the TDI value was significantly exceeded.

Health significance in baby food

Certain breast milk-like fatty acid patterns are prescribed for baby foods. The grease required for this must also be cleaned. The formation of traces of 3-MCPD fatty acid esters seems to be technologically unavoidable at the moment. In the recent past, new analytical methods have therefore also enabled the detection of 3-MCPD fatty acid esters in baby food. Intensive work is currently being carried out on reducing the levels through modified manufacturing processes. On the other hand, the supply of sufficient fat for optimal development is very important, especially for the infant. The fatty acid composition is based on the model of breast milk and requires high-quality vegetable fats as raw material.

For baby foods, the high-quality fats have to be cleaned, since the impurities in cold-pressed oil would be harmful to the baby's health. There is as yet no scientific data on the adverse effects of 3-MCPD fatty acid esters in humans, particularly in infants. It is not yet known whether and to what extent the 3-MCPD fatty acid esters are converted into free 3-MCPD and absorbed in the infant's digestive tract. Assuming the worst case, that 3-MCPD-fatty acid ester is completely converted to free 3-MCPD, there would be exceeding the tolerable daily intake ( tolerable daily intake , TDI).

However, the TDI can only be used as a basis for infants, as this is usually not used in the first few months of life. When assessing a possible health risk from 3-MCPD fatty acid esters in infant formula and follow-on formulas, a number of questions have therefore remained unanswered. In particular, it has not yet been clarified whether the hyperplastic effect of the substance on the renal tubules occurs in humans at all. Based on the current state of knowledge, the BfR assumes that in the worst case the safety margin to the effects observed in animal experiments must be set higher. It therefore sees a need for action with regard to the minimization of the levels, but assumes “no acute health risk”. The BfR therefore recommends that parents “continue to feed their babies as usual”. There is no alternative to formulas and follow-on formulas for infants who are not breastfed. Parents should therefore not switch to other milk such as cow, goat or mare's milk, as these lack important nutrients. The Austrian authorities, such as the Agency for Health and Food Safety (AGES), even see “no evidence of a health risk”.

Stereoisomerism

Like 3-MCPD, 3-MCPD fatty acid esters are chiral .

Individual evidence

↑ ^a ^b ^c 3-MCPD esters in refined edible fats and oils - a newly recognized, worldwide problem. Chemical and Veterinary Investigation Office, Stuttgart, December 18, 2007.

↑ ^a ^b Federal Institute for Risk Assessment (BfR): Questions and answers on the contamination of food with 3-MCPD, 2-MCPD and glycidyl fatty acid esters . July 7, 2016, accessed July 8, 2016.

↑ ^a ^b ^c Association of the oilseed processing industry in Germany: 3-MCPD fatty acid esters in food research and cooperation for reduction ( memento of the original from February 3, 2010 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked . Please check the original and archive link according to the instructions and then remove this notice. (PDF; 57 kB). @1@ 2

↑ 3-MCPD in food . food.org. Retrieved November 1, 2009.

↑ ^a ^b Association of the Oil Seed Processing Industry in Germany: 3-MCPD fatty acid ester background ( Memento of the original from February 3, 2010 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 294 kB). @1@ 2