`Index Predicts Antioxidant Activity of EVOO - Olive Oil Times

Index Predicts Antioxidant Activity of EVOO

By Sukhsatej Batra
Mar. 26, 2015 14:53 UTC

Although phe­no­lic com­pounds are respon­si­ble for the bit­ter­ness, fla­vor and color of extra vir­gin olive oil, they are more renowned for their health ben­e­fits and antiox­i­dant prop­er­ties. Knowing the antiox­i­dant activ­ity of extra vir­gin olive oil could help pre­dict its effec­tive­ness as a pro­tec­tive agent against dis­eases such as coro­nary heart dis­ease, stroke and some can­cers that are caused by oxida­tive dam­age.

The antiox­i­dant activ­ity of com­mer­cially avail­able olive oils varies because the vari­ety of olives, the cli­mate where they are grown, olive ripeness at time of har­vest, and meth­ods used for extrac­tion of olive oil all play a role in the polyphe­nol con­tent and chem­i­cal makeup of the oil.

In order to develop and val­i­date an antiox­i­dant activ­ity pre­dic­tive model for olive oil, researchers from the University of Basilicata and the University of Verona in Italy eval­u­ated the antiox­i­dant activ­ity of EVOOs using chem­i­cal indices and inves­ti­gated the rela­tion­ship between the chem­i­cal para­me­ters and antiox­i­dant activ­ity.

In the arti­cle, pub­lished in the jour­nal Food Chemistry, researchers deter­mined the antiox­i­dant activ­ity of 75 EVOOs from five dif­fer­ent cul­ti­vars — Coratina, Leccino, Maiatica, Ogliarola del Vulture and Ogliarola del Bradano — pro­duced in the Basilicata region in South Italy between 2011 ‑2012.

They eval­u­ated the bit­ter­ness of olive oils using a sim­ple index called the K225 value. This method mea­sures the quan­tity of total phe­nols and com­pounds respon­si­ble for oil bit­ter­ness absorbed at 225 nm in a spec­tropho­tome­ter. To mea­sure the rad­i­cal scav­eng­ing activ­ity of olive oil, expressed as IC50, the researchers used the DPPH assay.

Based on results obtained from the tested EVOO sam­ples, the authors built a pre­dic­tive model by relat­ing K225 val­ues to IC50 val­ues and found that the antiox­i­dant activ­ity, expressed as IC50 val­ues, could be pre­dicted by using the K225 val­ues.

The researchers fur­ther val­i­dated the pre­dic­tive model by com­par­ing mea­sured antiox­i­dant activ­ity of 20 unknown EVOO sam­ples to the val­ues of IC50 obtained using the pre­dic­tive model. The authors con­cluded that the model using K225 val­ues to cal­cu­late IC50 val­ues could be used to pre­dict the antiox­i­dant activ­ity of EVOOs.

The find­ings could offer a sim­ple method to mon­i­tor the qual­ity of EVOOs dur­ing pro­cess­ing so that high-qual­ity extra vir­gin olive oil with known antiox­i­dant activ­ity reaches con­sumers.



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