The University of California, Davis, Olive Center and Australian Oils Research Laboratory have issued an April 2011 report on olive oils sold in California, concluding that 73 percent of sampled oils allegedly fell short of International Olive Council (IOC) standards for extra-virgin oil. Building on a July 2010 report, the latest results were based on two IOC-accredited sensory panels, which analyzed 134 samples from eight brands sold in three different California regions.

According to the report, the two panels concluded that: (i) “Of the five topselling imported ‘extra virgin’ olive oil brands in the United States, 73 percent of the samples failed the IOC sensory standards”; (ii) “All of the oil samples passed the IOC chemistry standards for free fatty acids (FFA), fatty acid profile (FAP) and peroxide value (PV), but several of the imported samples failed the IOC’s ultraviolet absorption (UV) tests”; (iii) “70 percent of the samples from the five top-selling imported brands failed the German/Australian 1,2-diacylglycerol content (DAGs) test and 50 percent failed the German/Australian pyropheophytin (PPP) test”; and (iv) “The strongest relationship between chemical analysis and negative sensory results was found in the DAGs test (65 percent), followed by the PPP test (49 percent), UV K268 for conjugated trienes (34 percent), UV K232 for conjugated dienes (12 percent) and UV ΔK (6 percent).”

The report also apparently indicated that samples failed to meet extra virgin olive oil standards due to “one or more of the following: (a) oxidation by exposure to elevated temperatures, light, and/or aging; (b) adulteration with cheaper refined olive oil; and (c) poor quality oil made from damaged and overripe olives, processing flaws, and/or improper oil storage.” It has therefore recommended further research to establish “chemical markers for sensory defects,” as well as profiles for California olive oils.

Meanwhile, the IOC has publicly rebutted the study, calling it an “aggressive, inexplicable criticism of imported olive oil quality” that could cause “irreparable damage to the reputation of olive oil.” Joining in this censure, the North American Olive Oil Association (NAOOA) has also lambasted the report for allegedly relying on “rejected chemical tests and subjective taste analyses organized and conducted by organizations aligned with Australian and California agricultural interests to try to discredit importers of products with proven track records of consistent quality.” See IOC Statement, April 13, 2011; NAOOA News Release, April 16, 2011.