Fingerprinting (Py-GC/MS) of a bio-film active food package with Origanum vulgare L. essential oil.

The use of biobased packaging materials are becoming an alternative to polymers produced from non-renewable resources. Moreover, increasing interest in the use of active additives from natural sources has been observed in consumers and industry. Oregano essential oil (EO) is being included in new materials due to its bioactive properties. However, due to EOs high volatility, aspects like ageing and conditions of films preparation may cause losses of active agent. In this work, analytical pyrolysis (Py–GC/MS) was used to fingerprint a bioactive polylactic acid (PLA) with polybutylene succinate (PBS) (95:5) film extruded with variable quantities of oregano essential oil. Bio-plastic pyrolysis detected both, lactide enantiomers and monomer units from the PLA and specific molecular markers from the PBS fraction. Oregano EO pyrolysis released aromatics and terpenes with cymene, terpinene and thymol/carvacrol peaks identified as diagnostic peaks. Linear correlation coefficients < 0.950R2 (p < 0.001) were found between the chromatographic area of these diagnostic peaks and the amount of oregano EO included in the bioplastic matrix. Our results indicate that Py–GC/MS is a valuable tool providing not only a precise fingerprinting but also precise information about composition, quality and additives in active packages made with biogenic polymers