Quality Evaluation of Flavoured Extra-Virgin Olive Oils According to Their Chemical Composition

Within extra-virgin olive oil (EVOO) global market, there is a niche market of olive oils flavoured with aromatic and medicinal plants. The use of aromatic and medicinal plants to flavour extra-virgin olive oils enriches the oil both from a sensorial and nutritional point of view, affecting its chemical composition. It is, therefore, necessary to develop analytical techniques useful to investigate in deeply the quali-quantitative profile of molecules contained in both the volatile and non-volatile fractions of extra-virgin olive oil. In the current study, several flavoured EVOOs (with truffle, basil, cardamom, bergamot, lemon, mandarin, sage, porcini mushroom, garlic, and rose) were purchased from local stores and analysed by both HPLC and GC methods to verify the correspondence with the profile of the added aroma. Furthermore, considering the preciousness and cost of some specific flavouring ingredients, in some cases, multidimensional gas chromatographic approach coupled to IRMS or performed by a chiral separation (Es-MDGC) was led to investigate their authenticity. From the results obtained, these complementary approaches allowed confirming the genuineness for most of the flavoured EVOOs. For few flavourings, some differences were detected with respect to literature references, thus requiring additional analytical devices to further authenticate their genuineness.