Sunday, July 11, 2010

100% pure extra-vrgin Olive oil-is really diluted with other kinds of oil.

Posted: 07/09/2010-By: Heather Gordon

This fall, companies who sell sub-standard olive oil to the U.S. won't be able to slip in under the radar as easily anymore. The U.S. Department of Agriculture has received complaints about olive oil that is labeled as "100% extra virgin" -- but is really diluted with other kinds of oil.

According to the Los Angeles Times , industry experts say that extra virgin olive oil is "oil that is cold-processed to prevent degradation of aromatic compounds and has higher levels of healthy fats and antioxidants." The International Olive Council in Madrid has standards of low acidity levels, 0.8 grams per 100 grams or less, for oil to fit into that category.

However, companies have been able to get away with masking cheap olive oil with a top-end brand name and selling it in the U.S. for high prices for one simple reason -- there is no law against it. "The U.S. has been a dumping ground for cheap olive oil for years," said Vito S. Polito, a professor of plant sciences at UC Davis.

The biggest danger from unregulated olive oil comes from the chance of illness or allergic reactions caused by oil that is misrepresented as pure. When fish or nut-based oils make their way into the mix, people with allergies can have serious reactions. The Food and Drug Administration relies heavily on tips from the public and trade groups to uncover problems in the olive oil industry, since the agency doesn't regularly test olive oils for adulteration, says an FDA spokesman.

Slashfood says that some people worry new regulations would be meaningless unless they are made mandatory. So, how can you be certain the oil you buy is up to the new standards?
New regulations for U.S. imports would only apply to those with the federal seal of approval, so make sure you look for the seal to be sure you're buying the real deal.
Lab tests cast doubt on olive oil's virginity

UC Davis researchers report that most common brands sold in California are mislabeled, which can cost consumers money and worse. By P.J. Huffstutter and Kristena Hansen, Los Angeles Times- July 15, 2010

More than two-thirds of common brands of extra-virgin olive oil found in California grocery stores aren't what they claim to be, according to a report by researchers at UC Davis. The findings, which come as the federal government rolls out new standards aimed at cleaning up what has long been a slippery business, highlight mounting concerns over labeling accuracy for olive oil in the U.S. "This is only a beginning, but it's a clear warning," said Dan Flynn, executive director of UC Davis' Olive Center. Noting that the U.S. is the third-largest consumer of olive oil in the world, he added, "We need to be monitoring what is being sold to the public."

The purity issue is a major concern for some consumers. In the past, some state agencies have uncovered oils labeled as 100% extra-virgin olive oil that were blended with cheaper canola, seed or nut oils — a significant health threat to people with allergies. No such mixing was found in the recent tests of products sold in California, researchers said. Money is also at stake. Extra-virgin oil is marketed as a premium consumer product. At a Pavilions grocery store in Seal Beach, a 750-milliliter bottle of Bertolli's extra-virgin olive oil cost $14.29, while the same-size bottle of Bertolli's extra-light olive oil cost $7.99. (The store was not part of the report released Wednesday afternoon.)

The report underscores problems in an industry dominated by overseas importers and which has consumers slurping up more than $700 million of the stuff a year. The results were a combined effort of research conducted by scientists at UC Davis and at the Australian Oils Research Laboratory, a governmental research center accredited by the International Olive Council in Madrid, whose product standards the new U.S. Department of Agriculture rules are generally based upon. Industry officials generally agree that the "extra-virgin" designation is proper for oil that is cold-processed to prevent degradation of aromatic compounds and has higher levels of healthful fats and antioxidants. It also has relatively low acidity levels — 0.8 grams per 100 grams or less, according to the international group.

And federal law bars a company from not disclosing on the label that it is selling a blend of oils. But a key problem in the U.S. is that the practice of labeling lower-quality olive oil as top-end — and charging a premium for it — is technically legal. The reason is simple: There are no federal rules that define what "virgin" or "extra-virgin" olive oil is. (The new USDA standards, which are voluntary, go into effect this fall.) In March, UC Davis researchers visited retailers in Los Angeles, Sacramento and the Bay Area and bought bottles labeled as 100% extra-virgin olive oil from both domestic and imported producers. The stores included Ralphs, Safeway, Whole Foods Market and Wal-Mart.

The sampling size was relatively small. Researchers selected bottles from 14 popular import brands and five California producers. The samples were then put to a blind sensory — or taste and smell — examination by a panel of certified experts in Australia who are trained to detect flaws in such oils. The samples also were subjected to a battery of chemical tests. Some of the tests are industry standards. Others used newer approaches designed to uncover old or refined oils, said report co-author Rodney J. Mailer. UC Davis researchers reviewed their own set of blind samples. The result: 69% of the imported oils sampled and one of the 10 California-produced samples failed to meet internationally accepted standards for extra-virgin olive oil.

"Our laboratory tests found that samples of imported olive oil labeled as 'extra-virgin' and sold at retail locations in California often did not meet international and U.S. standards," the authors wrote in the report. The samples failed because of a variety of factors: heat, light exposure, age, adulteration with cheaper, refined olive oil, oils made from damaged or overripe olives, processing flaws and improper storage. Whole Foods spokeswoman Liz Burkhart said the chain stands behind its olive oil, which sells under the 365 Everyday Value 100% Italian Extra-Virgin Olive brand.

Whole Foods, the country's largest retailer of organic foods, uses a supplier that routinely tests the oil to "ensure it meets our requirements and the industry standards for extra-virgin olive oil," Burkhart said. Other retailers whose products were analyzed, including Safeway, Wal-Mart and Ralphs, declined to comment or could not be reached. Bob Bauer, president of the North American Olive Oil Assn., said he was "somewhat skeptical" of the results. He pointed out that funding for the research — $125,000 so far — was provided by three of California's largest olive oil producers and the California Olive Oil Council. That trade group that has been trying to grab market share from overseas competitors, whose brands dominate U.S. retail shelves. He also noted that some of the chemical tests weren't universally accepted by the industry.

"We've been conducting tests on oils in the marketplace since the early 1990s, from all over the country, and we've never come up with results like these," said Bauer, whose group represents most of the companies that import olive oil into the

Olive oil is a highly popular food product, due to its pleasant flavour and aroma and its perceived health benefits. Its high content of monounsaturated fats has been linked with a reduced risk of heart disease and other properties attributed to the oil include anti-inflammatory, anti-hypertensive and anti-thrombotic effects.  There are several commercial grades of olive oil of increasing quality, topped by extra virgin olive oil (EV). It is produced from the first pressing of the olives without any chemical treatment or heating and is closest to its natural state. Virgin (V) olive oil is produced from the second pressing, again with no further treatment, and has a slightly higher acidity then EV.

Refined olive oil (RO) is of lower quality than EV and V and has undergone treatment to reduce the acidity and improve the taste and ordinary olive oil (ON) is a blend of RO with added V to improve its flavour and colour. The quality of EV comes at a price, literally, being the most expensive of the olive oil grades. The price premium has led to countless cases of adulteration, as corrupt traders have diluted EV with other oils, in order to extend their profit margins.  Scientists have been very inventive in devising different analytical methods to detect olive oil adulteration, with many reports of successful chromatographic and spectroscopic methods. However, the search for new methods continues and two recent publications have illustrated the diversity of the approaches. Both involve mass spectrometry but in quite different ways.

In the first report, scientists in Brazil used electrospray ionisation mass spectrometry to detect the adulteration of EV with ON. Rodinei Augusti and colleagues from the Federal University of Minas Gerais, Belo Horizonte, and the Federal University of Uberlandia, decided against a chromatographic step before mass spectrometry. Instead they chose direct infusion backed up by chemometric techniques to process the complex spectra that were obtained. They analysed 10 brands of EV and 10 of ON by positive-ion electrospray mass spectrometry. The spectra of both oil types contained many peaks corresponding to mono-, di and triacylglycerols but their distributions appeared to be characteristic of each oil.

The spectra were processed by hierarchical cluster analysis (HCA), which produced two distinct clusters with no overlap, corresponding to EV and ON. A similar result was achieved with principal components analysis (PCA), the first three components accounting for 51.5, 16.12 and 12.49% of total variance, respectively. Olive oil factors such as cultivar, growth region and time of harvest had no effect on the discrimination. The team prepared a series of adulterated samples from each EV, containing 1-20 wt.% of ON and applied the same mass spectrometric and data processing procedures. HCA and PCA both clearly distinguished between the pure EV and adulterated samples, with no exceptions, down to 1 wt.% of ON, so should cover the vast majority of adulteration cases.

The second study was carried out by Cosima Calvano, Antonella Aresta and Carlo Zambonin from the University of Bari Aldo Moro, Italy, who wanted to distinguish EV adulteration with hazelnut oil (HO). This is often used as an adulterant due to its similar composition of triacylglycerols, sterols and fatty acids. They adopted a different approach, concentrating on the profile of the often neglected polar compounds present in the oils. Following an initial liquid-liquid extraction, the polar fractions of EV and HO were extracted by SPE using HILIC. The extracts were analysed by MALDI mass spectrometry on a time-of-flight instrument. A visual comparison revealed several peaks that were present in HO but absent in EV that could be used as biomarkers of HO adulteration. Three peaks in particular, at m/z 496, 520 and 522, were used to test adulteration by HO in EV. A plot of the ratio of each of the three peak intensities to that of an internal standard versus the percentage of HO in EV clearly illustrated that the three marker compounds could be observed down to 5% HO.

The identities of the markers were determined by LC/MS/MS with electrospray ionisation to be three species of lysophosphatidylcholine carrying different fatty acid chains. This method could easily be extended to detect the presence of other oils in EV, as long as the adulterants contained polar compounds that produced unique ions in their mass spectra. Both of these novel mass spectrometric methods could find use in forensic and food standard studies of extra virgin oil, to determine the presence of poor quality oils and ensure that only the most pristine oil reaches the consumer. Journal of Mass Spectrometry 2010 (Article in Press): "Detection of hazelnut oil in extra-virgin olive oil by analysis of polar components by micro-solid phase extraction based on hydrophilic liquid chromatography and MALDI-ToF mass spectrometry". Rapid Communications in Mass Spectrometry 2010, 24, 1875-1880: "Extra virgin (EV) and ordinary (ON) olive oils: distinction and detection of adulteration (EV with ON) as determined by direct infusion electrospray ionization mass spectrometry and chemometric approaches". Article by Steve Down

1 comment:

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