Occurrence of glycidyl esters in infant formula products on the Canadian market between 2015 and 2019

Glycidyl fatty acid esters (GEs) are processing contaminants formed during refining steps of vegetable oils. 'In vivo' hydrolysis of GEs releases potentially carcinogenic and genotoxic glycidol (2,3-epoxy-1-propanol). Occurrence of GEs in vegetable oils used for infant formula manufacturing may pose a potential health concern for formula-fed infants. Refined oils are commonly used as the main fat ingredient in formula manufacturing. For this study, different infant formula products (powders, concentrates and ready-to-feed formula products) were purchased and analysed in 2015 (35 samples) and 2019 (33 samples). Seven individual GEs were analysed by LC-MS/MS via direct approach by stable isotope dilution analysis, and total bound glycidol concentrations were calculated. Concentrations of bound glycidol in reconstituted formula reached maxima of 40.3 ng/g in the 2015 samples and 31.5 ng/g in the samples collected in 2019, with respective means of 8.7 ng/g and 6.7 ng/g. The analysed bound glycidol concentrations are comparable with concentration ranges from other studies, but are higher than observed in studies from the European market. Temporal trend data show a reduction of bound glycidol concentrations in 2019. GE concentrations were compared across different manufacturers.