Questioning the virginity of olive oils
By Catherine Watkins
Is a significant percentage of olive oil labeled as "extra virgin" and imported into the United States for retail sale out of spec with international and US standards?
A recent report from the University of California Davis (UC Davis) Olive Center suggests just that. A team of scientists led by Edwin N. Frankel found that 69% of imported olive oil samples and 10% of California olive oil samples labeled as extra virgin olive oil (EVOO) failed international chemical and sensory (organoleptic) standards for EVOO. The research team tested 52 samples of 19 brands-14 imported brands and five California brands-purchased in three geographical locations to reach their conclusions. The UC Davis Olive Oil Chemistry Laboratory, which has not yet been accredited by IOC, and the Australian Oils Research Laboratory (Wagga Wagga, New South Wales), which is fully accredited by IOC, conducted the laboratory work.
The laboratory tests also indicated that the International Olive Council (IOC; Madrid, Spain) and US Department of Agriculture (USDA) chemistry standards "often do not detect defective olive oils that fail extra virgin sensory standards," the UC Davis team said. The group suggested that IOC/USDA standards would be made "more effective" by including German/Australian 1,2-diacylglycerol (DAG) and pyropheophytins (PPP) standards.
"A reduced level of DAG indicates that the samples were oxidized, or poor quality, and/or adulterated with cheaper refined oils, while an elevated level of PPP indicates that the samples were oxidized and/or adulterated with cheaper refined oils," the report suggested.
In addition, the study found that:
- Sixty-nine percent of imported olive oil samples and 10% of California olive oil samples labeled as EVOO failed to meet the IOC/USDA sensory (organoleptic) standards for EVOO. The Australian sensory panel found that "each of these samples scored a median of up to 3.5 sensory defects such as rancid, fusty, and musty" and were classified at the lower grade of "virgin." Sensory defects are indicators that these samples are oxidized, of poor quality, and/or adulterated with cheaper refined oils.
- Thirty-one percent of the imported samples that failed the sensory standards also failed the IOC/USDA standards for UV absorbance of oxidation products (K232 and K268), which indicates that these samples were oxidized and/or were of poor quality.
- Eighty-three percent of the imported samples that failed the IOC/USDA sensory standards also failed the German/Australian DAG standard. Two additional imported samples that met the IOC/USDA sensory standard for EVOO failed the DAG standard.
- Fifty-two percent of the imported samples that failed the IOC/USDA sensory standards also failed the German/Australian PPP standard. Two additional imported samples that had met the IOC/USDA sensory standard for EVOO failed the PPP standard.
The IOC/USDA chemistry standards confirmed negative sensory results in 31% of cases, whereas the German/Australian DAG and PPP standards confirmed negative sensory results in 86% of cases.
IOC/NAOOA TAKE EXCEPTION
Both the IOC and the North American Olive Oil Association (NAOOA), a trade association representing olive oil importers, took exception to the study. IOC pointed out that the DAG/PPP methods "are not official chemical methods cited in international olive-oil-specific food or trade standards," adding that "they have, however, been adopted by the International Organization for Standardization (ISO)." IOC also called the methods "unreliable."
The methods in dispute were developed by Christian Gertz of the Official Institute of Chemical Analysis in Hagen, Germany. Both are officially approved methods of the Deutsche Gesellschalt für Fettewissenschaft (DGF), or German Society for Fat Science. The German government uses them in its official food inspection program. In addition, members of the Australian Olive Association (AOA) must meet the DAG and PPP standards to receive AOA certification for EVOO.
The IOC also noted in a statement that it conducts chemical tests on "some 200 samples of imported oils sold in the United States" each year and, according to IOC findings, anomalies are detected in less than 10% of the imported oils analyzed. Bob Bauer, president of NAOOA, pointed out that the market share of the brands with anomalies listed in the UC Davis report averages about 1% of the North American market. "We've never had a problem with any of the brands listed in the report," he said.
Imports account for about 99% of US consumption of olive oil, according to Bauer. Annual supermarket sales run approximately $700 million, not including club stores and other outlets. "Approximately 56% of the unit volume and 60% of the dollar volume is extra virgin," he reported. "Olive oil accounts for 26% of unit volume and 21% of dollar volume and extra light accounts for 13% in both areas," he added.
Dan Flynn, executive director of the UC Davis Olive Center, said in a statement that "UC Davis stands behind the report, which was conducted with an IOC-accredited lab using official IOC tests."
At the same time, Flynn emphasized that "UC Davis values the IOC's role in olive oil standards and tests. We invite the IOC to be a partner in our future research to analyze the quality of olive oil sold in the United States."
Patricia Darragh, executive director of the California Olive Oil Council (COOC; Berkeley, USA) agrees: "It is to the benefit of all to collaborate on research on olive oil quality as well as new methods for establishing that quality. The COOC looks forward to continued testing and research to ensure consumers receive a quality product that is properly labeled and meets grade standards."
The UC Davis report was written by Edwin N. Frankel, adjunct professor, UC Davis Department of Food Science and Technology; Rodney J. Mailer, principal research scientist, Australian Oils Research Laboratory; Charles F. Shoemaker, professor, UC Davis Department of Food Science and Technology; Selina C. Wang, research associate, UC Davis Olive Oil Chemistry Laboratory; and Dan Flynn. The study was supported by Corto Olive (Stockton, California, USA), California Olive Ranch (Oroville, USA), and the COOC. The group plans to submit the report for peer review and publication, according to Flynn.
The United States is the third-largest consumer of olive oil, according to the Reuters news service, but it produces far less than it consumes. Production in 2010/11 is expected to exceed 1 million gallons (about 4 million liters or 3,500 metric tons), Darragh said. At that point, US production will surpass French production. (Global production currently is about 2.7-2.8 million metric tons per year, according to Paul Miller, president of the AOA.)
A new voluntary US standard for olive oil grades goes into effect on October 25, 2010. The USDA will implement the standard and is in the process of training taste testers to conduct sensory tests at the Agricultural Marketing Service Science Specialty Laboratory in Blakely, Georgia.
Catherine Watkins is associate editor of inform and can be reached at email@example.com.
Lawsuit filed over UC Davis report
Several weeks after the release of the UC Davis Olive Center report, a number of California restaurateurs and chefs filed suit against certain olive oil distributors and retailers.
The lawsuit was filed in early August 2010 in Orange County (California, USA) Superior Court. It seeks class-action status, punitive damages, and reimbursement for profits made from alleged false marketing and advertising using the extra-virgin label.
A number of major olive oil brands were named in the suit, along with major supermarket chains and big-box superstores that allegedly marketed substandard oil under the extra-virgin label.
Bob Bauer, president of the North American Olive Oil Association (NAOOA), said that although the trade association representing olive oil importers was not named in the suit, NAOOA had talked to legal counsel, which said that some aspects of the suit are likely to be thrown out fairly quickly. "Others will have to play themselves out in court but are not likely to be upheld," Bauer added.
The attorneys for the plaintiffs in the lawsuit widely distributed a news release about their action that appeared to suggest AOCS contributed to the funding, research, and findings of the UCDavis study. In actuality, AOCS-as an international scientific association-does not conduct or fund external scientific research.
"The UC Davis study was not conducted under the auspices of AOCS," AOCS Executive Vice President Jean Wills Hinton emphasized, "nor were we asked to provide any input to the study. Although we have established expert panels-including one on olive oil-they are for the purpose of bringing together groups of internationally recognized scientists to discuss method development and other scientific matters related to fats and oils and specific topics of interest to government, academia, and industry.
"AOCS was not privy to the report results until after its release. We value our impartial role and are proud of our more than 100 years of service to the international fats and oils community," Hinton concluded.
- The issue of regional approaches to extra virgin olive oil quality was examined in a Hot Topic Symposium presented at the 99th AOCS Annual Meeting & Expo on Tuesday, May 20, 2008, in Seattle, Washington, USA. Visit http://tinyurl.com/AOCSOliveOil to download presentations from that session.
- More information on olive oil is available in Volume 1 of the AOCS Monograph Series on Oilseeds, Olive Oil: Chemistry and Technology, 2nd edition, 2006, ISBN: 978-1-893997-88-2 (list price, $115; member price, $85).
- AOCS offers an olive oil series in the Laboratory Proficiency Program (LPP) that includes testing for DAG (1,2-diacylglycerol), PPP (pyropheophytins), FAP (fatty acid profile), Peroxide Value, and other constituents. The recently added DAG and PPP are an effort to assist companies in better identification of olive oil quality. For more information about joining the olive oil series in the AOCS Proficiency Program contact Dawn Shepard in Technical Services.