Most 'extra virgin' olive oil bottles are actually cheaper mix -- even Rachael Ray's

olive oil
olive oil

More than two of every three bottles labeled imported extra virgin olive oil are either a cheaper grade of olive oil or adulterated with another type of oil, a University of California at Davis study found.

Top-selling brands including Bertolli, Filippo Berio, Carapelli, Pompeiian, Colavita, Mazola and Carapelli all had bottles that flunked the test -- containing instead a cheaper virgin olive oil, the study by the university's Olive Center found. Even a brand carrying the name of TV host Rachael Ray -- who frequently touts her supposedly extra virgin olive oil -- flunked the testing on two of three samples.