HIGH CONCENTRATION CAPACITY SAMPLING AS A FURTHER ANALYTICAL DIMENSION WITH HIGH INFORMATION POTENTIALS: EXTRA VIRGIN OLIVE OIL CLASSIFICATION

Olive oil is presently the only food product whose sensory attributes are officially regulated and sensory assessment has to be carried out through rigorous protocols by highly and continuously (permanently) trained panelists [1-2]. On the basis of the presence/absence and the intensities of specific defects and/or positive attributes, defined by smelling and tasting, Virgin Olive oil (VO) is classified into three categories namely Extra Virgin Olive oil (EVO), VO, and lampante oil [3]. Volatile compounds play a crucial role in defining olive oil sensory quality and strong efforts have been dedicated to unravel the composition of this informative fraction as well as to understand correlations with quality attributes. The potentials of HCC-HS (High Concentration Capacity Headspace) sampling have here been evaluated on the basis of a previous study, where the most informative compounds, present in the “blueprint” of specific defects (or combination of defects) were adopted to discriminate and classify EVO and lampante oils [4]. In particular, key-odorants and other informative components (located by a supervised approach, i.e., Partial Least Squares-Discriminant Analysis PLS-DA) have been extracted and their distribution within samples successfully characterized thanks to the combination of effective and selective sampling by HCC and D-HS techniques. Out of the sample preparation techniques investigated, Headspace Sorptive Extraction (HSSE) with differently polar and/or apolar extraction polymers, has shown to be really effective because of the high concentration factors, providing highly representative profiles as well as analyte recoveries suitable for reliable quantitation (precision and accuracy) of potent odorants in subtrace amounts. The possibility of extending the analytical investigation to a broader range of chemicals, will also be discussed in view of the potentials offered by multidimensional separation, by two dimensional comprehensive GC, that improves fingerprinting sensitivity and effectiveness of sample classification. References [1] Reg. CE n. 2568/91 and 796/02. [2] International Olive Council (IOC). Documents COI/T.20/Doc. No 5/Rev.3. and Rev. 4. [3] Reg. CE n 1989/03. [4] G. Purcaro, C. Cordero, E. Liberto, C. Bicchi, L. Conte, J. Chromatogr. A 10.1016/j. chroma.2014.01.067.