In the past decade, American olive oil consumption has doubled, thanks largely to the touted benefits of the Mediterranean diet and olive oil's status as a healthy fat. The U.S. is now the world's third-largest market for olive oil and in 2009, American consumers bought more than 75 million gallons, according to the International Olive Council (IOC), an intergovernmental organization based in Madrid that sets European standards for olive oil.
Extra virgin is the crème de la crème of olive oil, with consumers often paying twice as much for extra virgin as for virgin oil. Yet a recent study by the University of California at Davis Olive Oil Center, in collaboration with the Australian Oils Research Laboratory, questions whether the oil on store shelves is really extra virgin. It also raises serious concerns about international testing methods and U.S. government regulations for olive oil.
According to European Union law, extra-virgin olive oil means the oil has been made by physical means, either a press or a centrifuge—no chemical solvents—and meet 32 chemical requirements, including having free acidity of no more than 0.8 percent. (Free acidity can indicate oil decomposition.) Virgin oil must have free acidity of no more than 2 percent.
Dan Flynn, director of the U.C. Davis Olive Center, says the study was prompted by anecdotal reports of poor-quality olive oil being sold as extra virgin. "Now we have empirical proof that such is the case," says Flynn.
The researchers bought multiple samples of 19 different brands of extra-virgin olive oil, 14 imported brands and five from California, purchased at retail outlets in the Sacramento, San Francisco and Los Angeles areas. A panel of trained tasters evaluated the oils and then researchers conducted a series of lab tests both at the center and in Australia. "Eleven tests were done on each oil sample for a total of 572 tests," says Flynn.
The researchers found that 69 percent of the imported oils labeled extra-virgin failed to meet established international standards, while 10 percent of the California-produced brands failed. About 99 percent of olive oil consumed in the U.S. is imported. The tests indicated that the oils might have been oxidized, made from damaged and overripe olives, improperly stored or even adulterated with cheaper refined olive oil. The authors also suggest that IOC methods for evaluating oils may be inadequate, arguing that new German and Australian standards produced better results.
One important caveat: Two California producers, Corto Olive and California Olive Ranch, as well as the California Olive Oil Council, helped finance the UC Davis research.
The IOC noted in a statement that Davis "reports results for only 52 samples of 19 brands, which is not statistically significant." In a position paper written in response to the Davis study, the IOC also pointed out that the German and Australian testing methods are not official methods cited in international standards.
"UC Davis stands behind the report, which was conducted in an IOC-accredited lab using IOC tests," says Flynn.
The U.S. government relies largely on the EU to police European olive oil. In April, the Department of Agriculture (USDA) published a revised set of standards—entirely voluntary—that will go into effect next October. If a producer wants a USDA seal on their bottle, according to Flynn, they will have to comply with the revised guidelines for extra-virgin oil. However, producers can opt to label a product extra virgin without the accompanying USDA seal and avoid the rules.
Terry Bane, chief of the Processed Products Branch of the USDA's Agricultural Marketing Service, the agency responsible for the standards, says there are no plans to establish mandatory standards at this time and that any incentive to do so would have to come from industry. While the USDA is responsible for the oversight of agricultural products, the Food and Drug Administration (FDA) is responsible for overseeing the labeling and safety of food products such as olive oil, but has no inspection program for olive oils. The agency only checks products when a complaint has been filed.
Armando Manni, a Tuscany-based producer of internationally acclaimed extra-virgin olive oils, would not comment on the study. But he did warn, "I hope all the consumers know that when they are buying an extra-virgin olive oil, they are only buying an oil that at the moment of pressing has been declared an extra-virgin oil. From that moment, the oil starts the natural process of oxidation. This natural process can be dramatically altered by UV rays, oxygen and high temperatures."
Asked for suggestions that might help consumers choose a high-quality extra-virgin olive oil, Flynn says that consumers should "look for an impression of freshness in aroma and flavor ... like cut grass." A good oil should "taste like it came from fresh fruit." Flynn says an oil should be purchased and consumed within a year of harvest. He also suggested looking for a knowledgeable merchant.