Safe and Fast Fingerprint Aroma Detection in Adulterated Extra Virgin Olive Oil Using Gas Chromatography–Olfactometry-Mass Spectrometry Combined with Chemometrics

Abstract

The undeclared blending of extra virgin olive oils (EVOOs) with refined pomace olive oils (RPOO) is a well-known fraudulent practice. Despite the efforts made, it still remains a highly challenging authenticity issue to deal with. The present paper presents a fast fingerprint aroma technique, namely gas chromatography–olfactometry-mass spectrometry, which were tested as rapid screening tools for the detection of this adulteration.To overcome the lack of real adulterated samples was used to prepare EVOO mixtures with RPOO at different percentages. Besides, the quality indices was used as good markers to detect the illicit blends from the authentic oils such as K232 with 4% RPOO, K270 with 3% RPOO, and the variation of specific extinction (ΔK) of the adulterated EVOO with 10% RPOO. The addition of > 20% RPOO to EVOO would not be detected by the amount of TC18:1, fatty acids, and peroxide value. Moreover, using the sum of octadecadienoic and octadecatrienoic TFA isomers (TC18:2 + TC18:3) was confirmed to be good purity indices for the adulteration with 10 and 20% of RPOO. However, the main triglyceride found in oils samples were SOL + POO, OOL + LnPP, and OOO + PoPP as expected from the high oleic acid and low contents in linoleic and linoleic acid. Regarding volatile composition, thirty-four relevant aroma compounds and twenty-one key odorants were quantified in EVOO, RPOO, and EVOO adulterated with 1–20% of RPOO.