UC Davis Olive Center

Depending on who you listen to, olive oil is either a healthful, handmade-in-Tuscany, cold first pressed product with ancient history or an adulterated oil blend from questionable origins whose distribution is influenced by an international ring of fraudsters.

As I explored last week, olive oil, particularly extra-virgin olive oil, is an amazing food product, but unfortunately has been subject to suspect market practices, creating consumer confusion and, in some cases, representing fraud. Although there are international and domestic standards to guide olive oil production, there is not enough enforcement to prevent low quality or adulterated product from reaching store shelves.

Furthermore, as the demand for olive oil increases, the pressure to satisfy that demand by cutting corners on quality could increase. This makes it difficult for the consumer who wants quality olive oil to know what to do.

But if knowledge is power, then the University of California - Davis Olive Center may prove to be a useful tool for empowering olive oil consumers and producers alike.

Launched in 2008, the center, part of the university's agricultural school (specifically the Robert Mondavi Institute for Wine and Food Science), claims to be North America's only education and research center focused on the cultivation of olives.

Their research page has a number of interesting reports, particularly the July 2010 report on the results of testing European and American olive oils. They subjected 14 imported oils (3 samples each) and 5 domestic oils (2 samples each) to a battery of 10 chemical and sensory tests.

The study's results showed that most of the samples of imported oil failed some of the tests, while 9 of the 10 California oil samples passed all of the tests, including oils from two of the producers in my taste test (California Olive Ranch and McEvoy Ranch).

It wasn't all bad news for the big-name imports. Two of the best performers were store brands: Costco's Kirkland Organic and Walmart's Great Value 100% performed well, with two of their three samples passing all of the tests and the other samples failing only one each (one Walmart sample did not pass the test for elevated levels of pyropheophytins, which can indicate oxidation or adulteration, and one Costco sample failed the sensory test, e.g. taste, odor and "mouthfeel"). Filippo Berio came close, with two samples failing only the sensory test.

On the other end, Mazola's three samples failed three or four tests each. And a couple had mixed results: Both Colavita and Safeway Select had one sample that passed all the tests but another that failed five.

I found this study to be very illuminating, although I reserve a certain level of skepticism because the study was funded by California olive oil producers Corto Olive and California Olive Ranch (the ones who fared well in the tests). However, these results are corroborated by America's Test Kitchen's olive oil taste tests, which showed that California olive oils hold promise for competing with established import brands.