Independent components analysis coupled with 3D-front-face fluorescence spectroscopy to study the interaction between plastic food packaging and olive oil
Résumé
Olive oil is one of the most valued sources of fats in the Mediterranean diet. Its storage was generally done
using glass or metallic packaging materials. Nowadays, plastic packaging has gained worldwide spread for
the storage of olive oil. However, plastics are not inert and interaction phenomena may occur between
packaging materials and olive oil. In this study, extra virgin olive oil samples were submitted to accelerated
interaction conditions, in contact with polypropylene (PP) andpolylactide (PLA)plastic packaging materials.
3D-front-face fluorescence spectroscopy, being a simple, fast and non destructive analytical technique, was
used to study this interaction. Independent components analysis (ICA) was used to analyze raw 3D-front-
face fluorescence spectra of olive oil. ICA was able to highlight a probable effect of a migration of substances
with antioxidant activity. The signals extracted by ICA corresponded to natural olive oil fluorophores
(tocopherols and polyphenols)as well as newly formed ones which were tentatively identified asfluorescent
oxidation products. Based on the extracted fluorescent signals, olive oil in contact with plastics had slower
aging rates in comparison with reference oils. Peroxide and free acidity values validated the results obtained
by ICA, related to olive oil oxidation rates. Sorbed olive oil in plastic was also quantified given that this
sorption could induce a swelling of the polymer thus promoting migration.