Occurrence of 3-monochloropropane-1,2-diol (3-MCPD) esters and glycidyl esters in infant formulas from Germany.

Fatty acid esters of 3-monochloropropane-1,2-diol (3-MCPD), 2-monochloropropanediol-1,3-diol (2-MCPD), and glycidol are heat-induced processing contaminants formed during the deodorisation step of edible oil refining. Because these compounds are potentially carcinogenic and/or genotoxic, their presence in refined oils and fats and foods containing these oils/fats poses possible health concerns. In particular, formula-fed infants may be exposed to these compounds due to their presence in commercial infant formulas. For this reason, in 2018, the European Union established maximum limits for glycidyl esters in oils/fats and infant formulas and recently, as of January 2021, implemented regulations for the sum of free 3-MCPD and 3-MCPD fatty acid esters as well. This work involved the analysis of 3-MCPD and glycidyl ester contents in 45 infant formula products purchased from German supermarkets in 2019. The data produced in this study showed that average contaminant concentrations across all manufacturers were exceptionally low, with 100% of the products analysed falling below the current EU regulation for glycidyl esters in powdered formulas and 96% of the products analysed meeting the recently implemented regulation for the sum of free and bound 3-MCPD. In addition, a comparison of the 2019 data set to occurrence data collected for German formulas purchased in 2015 showed that average bound 3-MCPD and glycidol concentrations have decreased (from 0.094 to 0.054 µg g-1 and from 0.010 to 0.006 µg g-1, respectively), likely indicating that additional/improved mitigation measures for reducing contaminant concentrations in infant formulas have been implemented over the 4-year period. The data collected in this occurrence study are suitable for estimating levels of exposure to these compounds for German infants.Abbreviations: 2-MCPD: 2-monochloropropane-1,3-diol; 3-MCPD: 3-monochloropropane-1,2-diol; ARA: arachidonic acid; CE: collision energy; CXP: collision cell exit potential; DHA: docosahexaenoic acid; DP: declustering potential; EP: entrance potential; EPA: eicosapentaenoic acid; EtOAc: ethyl acetate; IPA: isopropanol; LC-MS/MS: liquid chromatography-tandem mass spectrometry; MeOH: methanol; MTBE: methyl tert-butyl ether; SPE: solid-phase extraction.

Assessment of intestinal absorption/metabolism of 3-chloro-1,2-propanediol (3-MCPD) and three 3-MCPD monoesters by Caco-2 cells.

3-chloro-1,2-propanediol (3-MCPD) and 3-MCPD esters are contaminants present in a variety of processed foods, including infant formulas. Toxicological data are unavailable in humans, but rodent studies have demonstrated renal and testicular toxicity from 3-MCPD and 3-MCPD esters. There is evidence that 3-MCPD esters are hydrolyzed in the digestive system, releasing 3-MCPD that would be absorbed and induce damage. We assessed absorption and metabolism of 3-MCPD and three 3-MCPD monoesters, 1-oleoyl (1-Ol), 1-linoleoyl (1-Li) and 1-palmitoyl (1-Pa) commonly found in U.S. infant formula using differentiated Caco-2 cells. After 1-hour incubation, all three monoesters released free 3-MCPD and free fatty acids (FFA) into Caco-2 cell supernatants. Free 3-MCPD had a high apparent permeability (Papp = 30.36 ± 1.31 cm/s × 10-6) suggesting that it is freely diffusible and highly absorbed by intestinal epithelium. 1-Li released 3-4-fold more 3-MCPD than 1-Ol and 1-Pa over 1 h, suggesting that this variable release rates might contribute to the overall in vivo exposure to 3-MCPD. None of the monoesters or FFA were detected in basolateral supernatants, suggesting that these compounds do not cross the intestinal wall without further transformation. In summary, this study provides relevant data to advance knowledge of in vivo intestinal absorption and metabolism of 3-MCPD monoesters.

Updated occurrence of 3-monochloropropane-1,2-diol esters (3-MCPD) and glycidyl esters in infant formulas purchased in the United States between 2017 and 2019.

Fatty acid esters of 3-monochloropropane-1,2-diol (3-MCPD) and glycidol are potentially carcinogenic and/or genotoxic processing contaminants that are formed during the process of edible oil refining. Because of their toxicological properties, the presence of these compounds in refined oils and foods containing these oils, particularly infant formula, poses a potential food safety concern. For this reason, recent research efforts have focussed on the development of methods for the analysis of MCPD and glycidyl esters in infant formula in order to estimate levels of exposure. This work presents occurrence data for 3-MCPD and glycidyl esters in 222 infant formulas purchased in the United States between December 2017 and January 2019. The results of this study show a wide range of contaminant concentrations across four different manufacturers, with average bound 3-MCPD concentrations ranging from 0.035 µg g-1 to 0.63 µg g-1 and average bound glycidol concentrations ranging from 0.019 µg g-1 to 0.22 µg g-1. The data suggest that manufacturers B and C source palm oil produced with mitigation measures, leading to reduced amounts of 3-MCPD and glycidyl esters in their infant formulas. Additionally, comparison with a previously published study in our laboratory of the occurrence of 3-MCPD and glycidyl esters in infant formula purchased in the U.S. between 2013 and 2016 revealed that, since 2016, contaminant concentrations have decreased in products produced by manufacturers A, B, and C, while contaminant amounts in formulas from manufacturer D have slightly increased.