Comparative Authenticity Signatures of Six Essential Oils Used as Food Flavors: a Gas chromatography - Mass Spectrometry Approach

The scientific interest in natural food flavors is growing considering concerns of the population related to food safety. Aromatic plants and their concentrated forms (essential oils and phenolic extracts) are highly considered for health benefits, mainly due to antioxidant and antibacterial properties. Meanwhile the authenticity and safety of essential oils is a strong concern. Comparative signatures of six genuine, essential oils (Thyme, Juniperus, Oregano, Tea tree, Clove and Cinnamon) was obtained by Gas chromatography coupled with Mass Spectrometry, using a metabolomic approach, by an updated statistical tool available online Metaboanalyst 5.0. The keymolecules of each oil were identified and the multivariate analysis combined with correlation heatmaps reflected the predictability of around 15 putative biomarkers, such as thymol and p-cymene for Thyme, α-pinene, βmyrcene and sabinene for Juniperus, carvacrol for Oregano, terpinene derivatives for Tea tree, eugenol, eugenol acetate for Clove, cinnamaldehyde for Cinnamon. Since these oils are used frequently as ingredients in food supplements and food flavors, this study offers an accurate evaluation and interpretation of the authenticity of these oils based on biomarker identification, easy to be done also from food matrices. The adulteration of similar commercial oils, of synthetic or degraded specimens is also possible using this model.