The migration of propylene glycol, mono-, di-, and triethylene glycols from regenerated cellulose film into food.

Chocolates, boiled sweets, toffees, cakes and meat pies were wrapped in regenerated cellulose films (with or without coatings) that contained various mixtures of glycol softeners and which had been specially formulated for particular food applications. Samples were unwrapped at intervals (up to the end of the usual maximum shelf-life for the food) and analysed for their glycol content. Analysis involved homogenization of the food in hot water, removal of fats with hexane, precipitation of sugars with calcium hydroxide and analysis of the glycols by capillary gas chromatography with flame ionization detection (GC/FID) after trimethylsilyl (TMS) derivatization. Triethylene glycol was analysed by selected ion monitoring GC/mass spectrometry (GC/MS) as interference problems occurred with the GC/FID approach. The results of the study showed that higher levels of migration occurred for propylene glycol than for triethylene glycol and the presence of a coating reduced the migration of both softeners. Generally, mono- and diethylene glycol levels in the food samples were below 10 mg/kg, although some samples wrapped in polyethylene glycol-softened films contained levels approaching the current statutory limit of 50 mg/kg.