Chemistry of Extra Virgin Olive Oil: Adulteration, Oxidative Stability, and Antioxidants

Abstract

Much analytical work has been published on the chemistry of extra virgin olive oil (EVOO) as a basis for the detection and quantitative analyses of the type and amount of adulteration with cheaper vegetable oils and deodorized olive oils. The analysis and authentication of EVOO represent very challenging analytical chemical problems. A significant amount of literature on EVOO adulteration has depended on sophisticated statistical approaches that require analyses of large numbers of samples. More effort is needed to exploit reliable chemical and instrumental methods that may not require so much statistical interpretation. Large assortments of methods have been used to determine lipid oxidation and oxidative stability and to evaluate the activity of the complex mixtures of phenolic antioxidants found in EVOO. More reliable chemical methods are required in this field to obviate excessive dependence on rapid antiradical methods that provide no information on the protective properties of antioxidants. The extensive literature on olive oil sensory tests, using many descriptors varying in different countries, should be supplemented by more precise gas chromatographic analyses of volatile compounds influencing the odor and flavors of EVOO.

Phenolic profile of virgin olive oil from advanced breeding selections

“…In fact, phenolic compounds are correlated to VOO stability during storage by virtue of their antioxidant activity that reduces oxidation processes (Gallina-Toschi et al, 2005;Frankel, 2010). Moreover, these compounds may provide a defense mechanism that delays aging and prevents carcinogenesis, atherosclerosis, obesity, liver disorders and inflammations (Tripoli et al, 2005;Bendini et al, 2007;Servili et al, 2009).…”

Quality Assessment of Olive Oil by 1H-NMR Fingerprinting

“…Moreover, polymerization and cyclization of PUFA, which mainly occurs at elevated temperatures, are not significant at room temperature. Furthermore, volatile acids that are measured by the Rancimat and OSI methods are produced only at elevated temperatures (Frankel, 2010). For all these reasons, the results of the studies on the oxidative stability of olive oil at high temperatures are neither relevant nor can be extrapolated to normal storage conditions at room temperature.…”

“…Most of the studies on the oxidative stability of olive oil employed questionably hightemperatures which, unfortunately, cannot be considered reliable to predict the stability of olive oils at room temperature (Frankel, 2010), i.e. under normal storage conditions.…”

“…Much analytical work has been done on the authentication and quality assessment of this high added value agricultural product, as well as on the detection of its adulteration for both economic and health considerations (Frankel, 2010;Guillen & Ruiz, 2001). However, these issues continue to be major analytical challenges.…”

Image analysis for composition monitoring. Commercial blends of olive and soybean oil

“…On the other hand, due to lower costs along with dietary issues, commercial mixtures of olive and other edible oils, usually soybean, are commonly available in local markets. Literature reports different kinds of olive oil characterization (FRANKEL, 2010), for example, olive oil adulteration either using cheaper vegetable oils or lower grade olive oils; olive oil lipid oxidation and oxidative stability, olive oil volatile compounds, olive oil antioxidants. Consequently, fast and accurate characterization of pure olive oil and commercial mixtures represents an important challenge (GARCIA-GONZALEZ; APARICIO, 2010).…”