LAUSR

Abstract Authentication of organic olives and olive oils is of growing interest due to the marked development of organic olive agriculture worldwide. In this study, the potential of using the untargeted volatile fingerprinting of organic and conventional olives obtained with a low-cost and fast methodology based on headspace ultraviolet ion mobility spectrometry (HS-UV-IMS) was investigated for first time. The results showed the suitability of the optimised method since a 94.39% success rate of classification of olives samples was achieved. However, this HS-UV-IMS device did not provide good results for olive oil samples and so two different and more powerful analytical techniques (HS-gas chromatography coupled to IMS with tritium source (HS-GC-IMS) and capillary electrophoresis coupled to UV detector (CE-UV)) were employed respectively to analyse the volatile fingerprinting and the polar compounds extracted from organic and conventional olive oils from two varieties and harvests. It was found that both devices could provide good classification results, above 93.20%, if an adequate number of samples (n > 50) from a single harvest was used. However, it was demonstrated that CE-UV is the best option since it provided more robust classification results over years (95.76%) in comparison with HS-GC-IMS (75.16%). An improvement in classification percentages of HS-GC-IMS data was observed when samples from two harvests were separated into Picual (98.73%) and Hojiblanca (98.78%) variety sets. HS-GC-mass spectrometry with a single quadruple (HS-GC-MS) was employed to contrast the results obtained for the volatile fraction of olive and olive oils with HS-UV-IMS and HS-GC-IMS devices. Also, up to 12 compounds were identified in olive and olive oil samples using HS-GC-MS but only the 3-hexenyl acetate was able to differentiate organic and conventional olive oils.