Esters of 3-chloro-1,2-propanediol (3-MCPD) in vegetable oils: significance in the formation of 3-MCPD.

Quality and Safety Assurance Department, Nestlé Research Center, Nestec Ltd, CH-1000 Lausanne 26, Switzerland.
Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment 05/2008; 25(4):391-400. DOI: 10.1080/02652030701385241
Source: PubMed

ABSTRACT 3-Mono-chloropropane-1,2-diol (3-MCPD) is a contaminant that occurs in food in its free (diol) form as well as in an esterified (with fatty acids) form. Using a simple intestinal model, it was demonstrated that 3-MCPD monoesters and 3-MCPD diesters are accepted by intestinal lipase as substrates in vitro. Under the chosen conditions, the yield of 3-MCPD from a 3-MCPD monoester was greater than 95% in approximately 1 min. Release from the diesters was slower, reaching about 45, 65 and 95% of 3-MCPD after 1, 5 and 90 min of incubation, respectively. However, in human, the hydrolysis of 3-MCPD esters is unlikely to release 100% as 3-MCPD, as triglycerides and phospholipids are hydrolysed in the intestine liberating 2-monoglycerides. Assuming a similar metabolism for 3-MCPD esters as that known for acylglycerols in humans in vivo, the de-esterification in positions 1 and 3 would thus be favoured by pancreatic lipases. Therefore, 3-MCPD, and 3-MCPD-2 monoesters would be released, respectively, from the 1-/3-monoesters, and the diesters potentially present in food. Hence, information on the exact amounts of the partial fatty acid chloroesters, i.e. 3-MCPD mono- and diesters, is important to assess the contribution of foods to the bioavailability of 3-MCPD. Therefore, a rapid method for the determination of the ratio of 3-MCPD monoesters to diesters in fats and oils was developed using gas chromatography-mass spectrometry (GC-MS) and isotopically labelled 3-MCPD esters as internal standards. The analysis of 11 different samples of fat mixes typically employed in food manufacturing demonstrated that a maximum of about 15% of the total amount of 3-MCPD bound in esters is present in the monoesterified form. The potentially slower release of 3-MCPD from 3-MCPD diesters, and the mono- to diesters ratio suggest that 3-MCPD esters may in fact contribute only marginally to the overall dietary exposure to 3-MCPD. Further work on the bioavailability, metabolism and possible toxicity of chloroesters per se is warranted.

1 Bookmark
  • [Show abstract] [Hide abstract]
    ABSTRACT: The food contaminants 3-chloro-1,2-propanediol (3-MCPD) and 3-MCPD fatty acid esters have attracted considerable attention in the past few years due to their toxic properties and their occurrence in numerous foods. Recently, significant amounts of the isomeric compounds 2-chloro-1,3-propanediol (2-MCPD) fatty acid esters have been detected in refined oils. Beside the interrogation which toxic effects might be related to the core compound 2-MCPD, the key question from the risk assessment perspective is again-as it was discussed for 3-MCPD fatty acid esters before-to which degree these esters are hydrolyzed in the gut, thereby releasing free 2-MCPD. Here, we show that free 2-MCPD but not 2-MCPD fatty acid esters were able to cross a monolayer of differentiated Caco-2 cells as an in vitro model for the human intestinal barrier. Instead, the esters were hydrolyzed by the cells, thereby releasing free 2-MCPD which was neither absorbed nor metabolized by the cells. Cytotoxicity assays revealed that free 2-MCPD as well as free 3-MCPD was not toxic to Caco-2 cells up to a level of 1 mM, whereas cellular viability was slightly decreased in the presence of a few 2-MCPD and 3-MCPD fatty acid esters at concentrations above 10 µM. The observed cytotoxic effects correlated well with the induction of caspase activity and might be attributed to the induction of apoptosis by free fatty acids which were released from the esters in the presence of Caco-2 cells.
    Archive für Toxikologie 10/2014; DOI:10.1007/s00204-014-1395-3 · 5.08 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We are presenting data on the occurrence of 2- and 3-MCPD esters and glycidol esters (MCPDEs and GEs) in more than 100 different edible fats, oils, and related products containing fats/oils, such as cookies and cooking sprays. Most of these products were purchased from retail stores in Ottawa, Canada between 2011 and 2013 in duplicate, thus allowing for evaluation of temporal trends. GEs and MCPDEs were determined by stable isotope dilution analysis using glycidol-d(5) labelled standards by LC-MS/MS in APCI mode and GC-MS in SIM mode after derivation with cyclohexanone, respectively. Unprocessed oils did not contain detectable levels of GEs or MCPDEs or contained them in trace amounts. The exception was palm oil, which contained 100-550 ng/g MCPDEs. GEs and MCPDEs content was highly variable in processed oils/fats, reaching 10.6 and 17.1 mu g/g (expressed as glycidol and MCPDs equivalents, respectively). Walnut, rice bran, grape seed oils and palm oil shortening were found to have the highest levels of MCPDEs and GEs. Levels in cookies also varied greatly from 5 to 339 ng/g, expressed as glycidol equivalents and from 29 to 510 ng/g expressed as MCPD equivalents. Crown Copyright
    Journal of Food Composition and Analysis 10/2014; 37. DOI:10.1016/j.jfca.2014.09.002 · 2.26 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: 3-monochoropropane-1, 2-diol (3-MCPD) esters from edible oils are considered to be a possible risk factor for adverse effects in human. In the present study, the exposure assessment of 3-MCPD esters to Chinese population was performed. A total of 143 edible oil and fat samples collected from Chinese markets were determined for the concentrations of 3-MCPD esters. The concentration data together with the data of fats consumed were analyzed by the point evaluation and probabilistic assessment for the exposure assessment. The point evaluation showed that the mean daily intake (DI) of 3-MCPD esters were lower than the value of provisional maximum tolerable daily intake (PMTDI) of 3-MCPD (2 µg/kg BW/d). The mean DI values in different age groups obtained from probabilistic assessment were similar to the results of the point evaluation. However, in high percentiles (95th, 97.5th, 99th), the DI values in all age groups were undesirably higher than the value of PMTDI. Overall, the children and adolescents exposed more to 3-MCPD esters than the adults. Uncertainty was also analyzed for the exposure assessment. Decreasing the level of 3-MCPD esters in edible oils and consuming less oil were top priority to minimize the risk of 3-MCPD esters. Copyright © 2014 Elsevier Ltd. All rights reserved.
    Food and Chemical Toxicology 11/2014; 75C:8-13. DOI:10.1016/j.fct.2014.10.003 · 2.61 Impact Factor