To be extra-virgin, olive oil can't be rancid or doctored with lesser oils. Shoemaker wasn't all that surprised that many of the 14 major brands failed certain tests... "We do spectroscopic studies looking for oxidation," he says. That means the oil's old or spoiled. Shoemaker also tests fatty acids "to make sure the oil is all from olives and not from soybean, sunflower or other types of oil."
The study was funded by the California Olive Oil council, so it's not surprising that representatives of olive oil importers are questioning the validity of the data.
There's never been a legal definition in the U.S. for any grade of olive oil, but mounting concern over truth-in-olive-oil-labeling has drawn in the USDA, and new American regulations will conform to international standards. Starting in October, olive oil from every olive oil-producing country, including America, will be subject to random sampling off retail shelves.
http://www.npr.org/templates/story/story.php?storyId=128702706. Photo: Publications International, Ltd.