Résumé
While autoxidation of Polyunsaturated Fatty Acids (PUFAs) is a potential source of furan and its derivatives, the regulatory obligation to enrich powdered infant formulae (PIF) with some of these compounds might raise safety issues. The aim of this study was to investigate the impact of formulation and home storage conditions on the generation of furan and its derivatives in PIF. Furan, 2-methylfuran (2-MF) and 3-methylfuran (3-MF) were monitored by a validated SHS-GC-Q Exactive-Orbitrap MS method in six PIF formulated with high or low concentrations of different PUFAs (ALA, ARA, DHA), pro-oxidants (iron) and anti-oxidants (vitamins) and stored for 21 days under more or less oxidizing home storage conditions, including temperature (19 degrees C or 40 degrees C) and oxygen exposure (protected or not from ambient air). For the three compounds, the quality of the measurements in PIF was first confirmed with suitable linearity, limits of quantification, precision and recoveries. In a second step, the impact of the formulation was evaluated on six PIF commercial samples differing significantly in their composition in ALA, ARA, DHA, iron and/or vitamin E and C. While furan was quantifiable (2.8 mu g/kg) in only one PIF with high content of DHA and iron and low level of vitamins, 2-MF was only quantifiable in two other PIF which were distinguished by a 15 to 20 % higher ALA content and 3-MF was not detected in any of the six PIF studied. In a third step, the effect of storage conditions was studied on the six PIF and the increase in storage temperature to 40 degrees C led to an increase of up to 33 % in the 2-MF concentration in the two PIF formulations where it was quantifiable. Nevertheless, the estimation of the Margin of Exposure (MOE) showed that the risk related to furan and its derivatives could be ruled out regardless of the formulation or storage conditions. Finally, in order to explore other derivatives and to investigate the mechanisms involved in the generation of furan compounds in PIF, a suspect screening approach was implemented on the SHS-GC-Q Exactive-Orbitrap MS data. It made it possible on the one hand to point out two additional furan derivatives in PIF, 2-ethylfuran and 2-pentylfuran. On the other hand, it enabled to discuss the oxidation pathways involved in the generation of furan compounds in PIF from profiling of known PUFA oxidation markers also detected in the samples.