In an article published on October 12, 2018, in the peer-reviewed journal Food Additives & Contaminants: Part A, Maria Hoppe and colleagues from the Fraunhofer institute for Process Engineering and Packaging IVV, Freising, Germany, characterized the oligomer composition of polyethylene furanoate (PEF) polymer intended for food contact. The scientists studied “PEF granulate . . . provided by Corbion (Gorinchem, the Netherlands” and performed extraction for 24 hours with either acetonitrile at 40 °C or dichloromethane at room temperature.
The scientists identified 20 linear and cyclic oligomers in PEF extracts, which they further divided into four groups. Oligomers from the first group, containing “cyclic oligomers consisting of furandicarboxylic acid, monoethylene glycol units and one diethylene glycol unit,” accounted for 87% of the total oligomer content. Oligomers from the groups II and III, also cyclic, accounted for 12% and 1%, respectively. Linear oligomers, assigned into group IV, represented less than 0.05% of the total oligomer content. The scientists conclude that their study “demonstrate[s] that oligomers are abundant in the PEF material and are potential migrants to foods.” The quantification of migrating oligomers will be the subject of future studies, using the sensitive analytical method proposed here.
PEF is a polyester analogous to polyethylene terephthalate (PET) (FPF reported). Based on the sourcing possibilities for its monomers, PEF could potentially be a “100% bio-based polyester.” As a food contact material, its primary applications are planned to include “bottles for soft drinks, water, alcoholic beverages and fruit juices,” thus potentially replacing PET in some applications (FPF reported). The scientific opinion by the European Food Safety Authority (EFSA) issued in 2014 for one of the co-monomers of PEF, furan-2,5-dicarboxylic acid (CAS 3238-40-2), concluded that there would be no safety concern if “the migration of the substance itself does not exceed 5 mg/kg food and migration of the oligomers less than 1000 Da does not exceed 50 µg/kg.”
Hoppe, M., et al. (2018). “Oligomers in polyethylene furanoate – identification and quantification approach via LC-UV LC-MS response ratio.” Food Additives & Contaminants: Part A (published October 12, 2018).
EFSA (2014). “Scientific Opinion on the safety assessment of the substance, furan-2,5-dicarboxylic acid, CAS No 3238-40-2, for use in food contact materials.” EFSA Journal 12:3866.