Process contaminants in vegetable oils and foods
Glycidyl fatty acid esters – genotoxic and carcinogenic
EFSA was asked to deliver a scientific opinion on free and esterified 3- and 2- monochloropropane-1, 2-diol (MCPD) and glycidyl esters in food.
Esters of 3- and 2-MCPD and glycidol are contaminants of processed vegetable oils; free MCPDs are formed in some processed foods.
The Panel on Contaminants in the Food Chain (CONTAM Panel) evaluated 7,175 occurrence data.
Esters of 3- and 2-MCPD and glycidyl esters were found at the highest levels in palm oil/fat, but most vegetable oil/fats contain substantial quantities. Mean middle bound (MB) dietary exposure values to total 3-MCPD, 2-MCPD and glycidol, respectively, across surveys and age groups in μg/kg body weight (bw) per day were 0.2–1.5, 0.1–0.7 and 0.1–0.9; high exposure (P95) values were 0.3–2.6, 0.2–1.2 and 0.2–2.1. Animal studies show extensive hydrolysis of esterified 3-MCPD and glycidol following oral administration; esterified and free forms were assumed to contribute equally to internal exposures.
Nephrotoxicity was consistently observed in rats treated with 3-MCPD.
Data on 2-MCPD toxicity were insufficient for dose–response assessments. Chronic treatment with glycidol increased the incidence of tumours in several tissues of rats and mice, likely via a genotoxic mode of action. The Panel selected a BMDL10 value for 3-MCPD of 0.077 mg/kg bw per day for induction of renal tubular hyperplasia in rats and derived a tolerable daily intake (TDI) of 0.8 μg/kg bw per day.
The mean exposure to 3-MCPD was above the TDI for ‘Infants’, ‘Toddlers’ and ‘Other children’. For glycidol, the Panel selected a T25 value of 10.2 mg/kg bw per day for neoplastic effects in rats. The margins of exposure (MoEs) were 11,300–102,000 and 4,900–51,000 across surveys and age groups at mean and P95 exposures, respectively. An exposure scenario for infants receiving formula only resulted in MoEs of 5,500 (mean) and 2,100 (P95). MoEs of 25,000 or higher were considered of low health concern.
© European Food Safety Authority, 2016
Keywords: MCPD, glycidol, glycidyl fatty acid esters, process contaminant, refined oil fat
Exposure to 3-MCPD over safe level; insufficient data on 2-MCPD
This risk assessment will inform risk managers in the European Commission and Member States who regulate EU food safety. They will use EFSA’s scientific advice to consider how to manage the potential risks for consumers from exposure to these substances in food. The Panel has also made several recommendations for further research to fill data gaps and improve the knowledge on the toxicity of these substances, particularly 2-MCPD, and on consumer exposure to them through food.
Scientific opinion on risks for human health related to the presence of 3- and 2-monochloropropanediol (MCPD), and their fatty acid esters, and glycidyl fatty acid esters in food
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Official Journal of the European Union
3-Monochloropropane-1,2-diol (3-MCPD) is a food processing contaminant classified as a possible human carcinogen for which a tolerable daily intake (TDI) of 2 μg/kg b.w. has been established (1). A maximum level of 20 μg/kg for hydrolysed vegetable protein (HVP) and soy sauce has been established by Commission Regulation (EC) No 1881/2006 (2) for liquid products containing 40 % dry matter, corresponding to a maximum of 50 μg/kg in the dry matter.
Esters of 2- and 3-monochloropropane-1,2-diol (MCPD) and glycidyl esters are important contaminants of processed edible oils used as foods or food ingredients. The European Food Safety Authority (EFSA) Panel on Contaminants in the Food Chain (CONTAM) agreed with the estimate of 100 % release of 3-MCPD from its esters in humans (3).
Glycidyl fatty acid esters (GE) are process contaminants generated during the deodorisation step of edible oil refining. The toxicological relevance of glycidyl fatty acid esters has not yet been fully elucidated. Glycidol itself is categorised as probably carcinogenic to humans. Latest scientific studies indicate an (almost) entire release of glycidol from fatty acid esters within the human digestive tract.
On 20 September 2013, EFSA has published a scientific report on the analysis of occurrence of 3-monochloropropane-1,2-diol (3-MCPD) in food in Europe in the years 2009-2011 and preliminary exposure assessment (4).
More occurrence data on the presence of the MCPD fatty acid esters and glycidyl fatty acid esters are necessary to enable a more accurate exposure assessment.
Therefore it is appropriate to recommend the monitoring of the presence of MCPD, MCPD-esters and glycidyl esters in vegetable oils and fats, derived foods and foods containing vegetable oils and fats.
Member States should, with the active involvement of feed and food business operators, perform monitoring for the presence of 2 and 3-MCPD, 2 and 3-MCPD fatty acid esters and glycidyl fatty acid esters in food, and particularly in:
It is recognised that the analysis of 2 and 3-MCPD, 2 and 3-MCPD fatty acid esters and glycidyl fatty acid esters in foods mentioned in points (b) to (f) is very challenging and no methods of analysis, which have been validated by a collaborative study, are yet available. Therefore particular attention has to be paid when analysing foods mentioned in points (b) to (f) in order to ensure that the generated data are reliable.
Therefore, Member States which intend to analyse the presence of 2 and 3-MCPD, 2 and 3-MCPD fatty acid esters and glycidyl fatty acid esters in foods mentioned in points (b) to (f) may request, if appropriate and needed, the technical assistance of the Commission's Joint Research Centre, Institute for Reference Materials and Measurements (IRMM), Unit Standards for Food Bioscience.
In order to ensure that the samples are representative for the sampled lot, Member States should follow the sampling procedures laid down in Part B of the Annex to the Commission Regulation (EC) No 333/2007 (8).
In order to determine ester bound MCPD and glycidol, it is recommended to use the American Oil Chemists' Society standard methods. These methods are Gas-Chromatography Mass Spectrometry methods (GC-MS) which have been validated by a collaborative study for vegetable oils and fats and are available at www.aocs.org.
The Limit of Quantification (LOQ) should not be higher than 100 μg/kg for the analysis of MCPD and glycidol bound to fatty acid esters in edible oils and fats. For other foods containing more than 10 % fat, the LOQ should preferably be not higher when related to the fat content of the food, i.e. the LOQ for the analysis of fatty acid esters of MCPD and glycidol in food containing 20 % fat should not be higher than 20 μg/kg on whole weight basis. For foods containing less than 10 % fat, the LOQ should be not higher than 10 μg/kg on whole weight basis.
Laboratories should have quality control procedures in place to avoid the transformation of glycidyl esters into MCPD esters and vice versa during the analysis. Furthermore unambiguous specification of the measurand and separate reporting is necessary of the free 2- and 3- MCPD present in the analysed matrix from the 2- and 3-MCPD fatty acid esters, as both are measured as 3-MCPD. Following measurands should be reported separately:
There is no evidence for the time being of the presence of free glycidol in foods referred to in Point (1). However in case where free glycidol would be analysed, this should be reported separately.
Member States should ensure that the analytical results are provided on a regular basis (every six months) to EFSA in the EFSA data submission format in line with the requirements of EFSA's Guidance on Standard Sample Description (SSD) for Food and Feed (9) and the additional EFSA's specific reporting requirements.
A simplified format, with fewer mandatory fields to be completed, will be made available to ensure maximum submission of useful available monitoring data.
A guidance note will be elaborated to ensure uniform application of this Recommendation and to ensure comparable reporting of results.