The impact of infant formula production on the concentrations of 3-MCPD and glycidyl esters.

Fatty acid esters of 3-monochloropropanediol (3-MCPD), 2-monochlorpropanediol (2-MCPD), and glycidol are process-induced chemical contaminants found in refined vegetable oils. Due to their toxicological properties, there is potential concern regarding exposure to these compounds, particularly for formula-fed infants where refined edible oils are the primary fat source in commercial infant formulas. In order to assess exposure, 55 commercial oil samples, specifically intended for use in infant formula, were collected in 2015 from various infant formula manufacturers in the United States and analysed using a LC-MS/MS direct detection method. At the time of collection, there were no validated methods for the analysis of MCPD and glycidyl esters in infant formula. Therefore, analysis of these commercial oil samples served as an alternative for confirming the presence of these ester contaminants in infant formula. Bound 3-MCPD and glycidol concentrations in these oils ranged from below the limit of quantitation (<LOQ) to 5.13 µg g-1 and <LOQ to 6.14 µg g-1, respectively. Highest ester concentrations were observed in palm olein samples. Concentrations of bound 3-MCPD and glycidol in the commercial oils were consistent with previously published occurrence studies at the time, suggesting that oils used in the manufacture of infant formula were similar (or processed in a similar manner) as refined oils marketed directly to consumers in 2015. In order to determine if conditions during infant formula production impact the presence of 3-MCPD and glycidyl esters in the finished products, concentrations in oils were compared to concentrations in finished infant formula collected at approximately the same time. The comparison revealed that conditions used in the manufacture of infant formula likely initiate the destruction or conversion of glycidyl esters to other compounds, resulting in lower amounts of bound glycidol in the final product relative to the concentrations originally present in the refined oils.