3-MBPD & 3-MIPD: New challenges in analysis of 3-MCPD esters & glycidyl esters

3-Monochloropropane-1,2-diol fatty acid esters (3-MCPDE) and glycidyl fatty acid esters (GE) are known foodborne contaminants that are suspected of showing adverse health effects when digested. Since 3-MCPDEs and GEs are mainly formed during the refining of edible oils and fats, they are ubiquitous in the latter, but also in various types of oil- and fat-containing foods and corresponding dietary supplements and additives. The European Commission has set maximum levels for 3-MCPD, 3-MCPDE and GE in edible oils and fats, infant formulae and other foods (EU 2023/915). Since the presence of 3-MCPDE and GE has been intensively discussed for more than a decade and food safety is recognized worldwide, numerous analytical methods have been developed for the determination of trace levels of 3-MCPDE, GE and related compounds in various foods. For routine application, so-called indirect methods have predominantly become established, which aim at the release of the core analytes after ester cleavage followed by conversion of the unstable and volatile free glycidol to a suitable stable derivative. In indirect methods, this is achieved either by conversion of glycidol to induced 3-MCPD or, more commonly, to 3-Monobromo-1,3-propanediol (3-MBPD). These solutions are based on the assumption that no other interfering 3-substituted propane-1,2-diols (3-MXPD) are present in the samples tested.

This presentation will provide recent research results on the occurrence of interfering 3-MXPD fatty acid esters in certain refined oils and fats. The results with special attention to 3-MBPDE and 3-Monoiodopropane-1,2-diol (3-MIPDE) are discussed with regard to a possible lack of specificity of existing analytical methods and the potential consequences for their suitability for official food control. Finally, new analytical approaches are presented that aim to cover not only 2- and 3-MCPDE and GE, but also the parallel determination of 3-MBPDE and 3-MIPDE as well as the isomeric 2-MXPDE in edible oils and fats.