Answering the question: "Is extra virgin olive oil price a measure of its quality?"

Extra virgin olive oil (EVOO) is a key product in the Mediterranean diet, whose healthy properties can be to a large extent attributed to EVOO. Anyhow the quality level of this product has a broad range, as also suggested by the broad price range with which we find this product on the market. Several parameters, more and less conventional, contribute to determine the overall quality of an EVOO, and many of them are not regulated by legislation. Among the most important chemical features contributing to the sensory properties of EVOO, volatile substances and polyphenols play a key role, with polyphenols deeply contributing also to the healthy properties of the oil. This study, as a part of the wider project “AEVOO: Authentication of Extra Virgin Olive Oil”, aimed to characterize EVOOs from the market, belonging to different price levels, in order to highlight the key differences between these apparently equal, but sometimes deeply different, food products. To accomplish this task, several parameters have been investigated, some of them conventional and officially recognized (as acidity, peroxide value, fatty acid composition) and some other, less conventional but strictly related to the quality, as volatile substances, polyphenols, tocopherols. Furthermore, different approaches have been evaluated to assess the antioxidant activity of the oils under investigation, by measuring the polyphenol content by means of spectrophotometry (Folin-Ciocalteu method) as well as high performance liquid chromatography, and then by amplified-chemiluminescence assays to evaluate the scavenger capacity of bioactive molecules towards superoxide anion and hydrogen peroxide [1]. Total Antioxidant Activity and Oxygen Radical Absorbance Capacity have been also employed in order to provide indications about the capacity of antioxidants contained in EVOOs to neutralize the ABTS and the DPPH radicals, respectively [2,3]. The studies are revealing interesting differences between the oil classes under investigation and chemical markers of the quality allowed to differentiate EVOO classes by principal components analysis. Preliminary results will be presented and discussed. References [1] C. Nasuti, R. Gabbianelli, G. Falcioni, F. Cantalamessa. Antioxidative and gastroprotective activities of drug formulations derived from chestnut honey in rats. Nutrition research 2006, 26, 130. [2] N. Pellegrini, F. Visioli, S. Buratti, F. Brighenti. Direct analysis of total antioxidant activity of olive oil and studies on the influence of heating. J. Agric. Food Chem. 2001, 49, 2352-2538. [3] B.A. Zullo, G. Ciafardini. The olive oxygen radical absorbance capacity (DPPH assay) as a quality indicator. Eur. J. Lipid Sci. Technol. 2008, 110, 428-434.