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Phenolic comÂpounds in extra virÂgin olive oil conÂtribute to its taste, color, and bitÂterÂness, but are more recÂogÂnized for their health benÂeÂfits and antioxÂiÂdant propÂerÂties, which can help proÂtect against disÂeases caused by oxidaÂtive damÂage. Researchers from the University of Basilicata and the University of Verona in Italy develÂoped a preÂdicÂtive model using chemÂiÂcal indices to meaÂsure the antioxÂiÂdant activÂity of EVOOs, allowÂing for the monÂiÂtorÂing of high-qualÂity olive oils durÂing proÂcessÂing to ensure conÂsumers receive prodÂucts with known health benÂeÂfits.
Although pheÂnoÂlic comÂpounds are responÂsiÂble for the bitÂterÂness, flaÂvor and color of extra virÂgin olive oil, they are more renowned for their health benÂeÂfits and antioxÂiÂdant propÂerÂties. Knowing the antioxÂiÂdant activÂity of extra virÂgin olive oil could help preÂdict its effecÂtiveÂness as a proÂtecÂtive agent against disÂeases such as coroÂnary heart disÂease, stroke and some canÂcers that are caused by oxidaÂtive damÂage.
The antioxÂiÂdant activÂity of comÂmerÂcially availÂable olive oils varies because the variÂety of olives, the cliÂmate where they are grown, olive ripeness at time of harÂvest, and methÂods used for extracÂtion of olive oil all play a role in the polypheÂnol conÂtent and chemÂiÂcal makeup of the oil.
In order to develop and valÂiÂdate an antioxÂiÂdant activÂity preÂdicÂtive model for olive oil, researchers from the University of Basilicata and the University of Verona in Italy evalÂuÂated the antioxÂiÂdant activÂity of EVOOs using chemÂiÂcal indices and invesÂtiÂgated the relaÂtionÂship between the chemÂiÂcal paraÂmeÂters and antioxÂiÂdant activÂity.
In the artiÂcle, pubÂlished in the jourÂnal Food Chemistry, researchers deterÂmined the antioxÂiÂdant activÂity of 75 EVOOs from five difÂferÂent culÂtiÂvars — Coratina, Leccino, Maiatica, Ogliarola del Vulture and Ogliarola del Bradano — proÂduced in the Basilicata region in South Italy between 2011 ‑2012.
They evalÂuÂated the bitÂterÂness of olive oils using a simÂple index called the K225 value. This method meaÂsures the quanÂtity of total pheÂnols and comÂpounds responÂsiÂble for oil bitÂterÂness absorbed at 225 nm in a specÂtrophoÂtomeÂter. To meaÂsure the radÂiÂcal scavÂengÂing activÂity of olive oil, expressed as IC50, the researchers used the DPPH assay.
Based on results obtained from the testÂedexÂtra virÂgin olive oil samÂples, the authors built a preÂdicÂtive model by relatÂing K225 valÂues to IC50 valÂues and found that the antioxÂiÂdant activÂity, expressed as IC50 valÂues, could be preÂdicted by using the K225 valÂues.
The researchers furÂther valÂiÂdated the preÂdicÂtive model by comÂparÂing meaÂsured antioxÂiÂdant activÂity of 20 unknownexÂtra virÂgin olive oil samÂples to the valÂues of IC50 obtained using the preÂdicÂtive model. The authors conÂcluded that the model using K225 valÂues to calÂcuÂlate IC50 valÂues could be used to preÂdict the antioxÂiÂdant activÂity of EVOOs.
The findÂings could offer a simÂple method to monÂiÂtor the qualÂity of EVOOs durÂing proÂcessÂing so that high-qualÂity extra virÂgin olive oil with known antioxÂiÂdant activÂity reaches conÂsumers.