Olive oil phenolic fraction and evaluation of its antioxidant capacity

The health promoting properties of olive oil are due to its unique profile of phenolic fraction along with high amount of squalene and oleic acid. The protective effects of phenolic compounds can be attributed to their strong antioxidant activity, besides their antiproliferative, antihemorragic and anti-inflammatory properties. The concentration of phytochemical compounds in olive oil depends on several factors, including: cultivar, soil, climate, production procedures and storage conditions. In the present study, the total phytochemical content and its antioxidant capacity were measured in 6 olive oil samples from different cultivars, locations and sources. The total polyphenols determination and the detection and quantification of the single polyphenols, revealed that home-made olive oil samples presented various profiles and contents of phenolic fraction, probably due to the differences of variety and location. Olive oil samples from the same variety, extracted with the same technology, and taken from the same region, but harvested and produced in two different years, 2003 and 2004 respectively, showed a different phenolic profile. The 2003 sample was richer of simple phenolic acids, while the 2004 presented a higher amount of complex polyphenols (secoiridoids). At the same time, the latter showed a minor antioxidant activity, measured by the Oxygen Radical Absorbance Capacity Assay (ORAC), than the 2003 sample.