It is a non-targeted approach where certain components in olive oil are assessed using mass spectrometry to detect their presence and possible concentration.
Based on a large number of samples from major olive oil producing countries, a specific profile for extra virgin olive oil is generated, using the presence and quantity of the compounds determined by the mass spectrometry analysis.
As we reported yesterday, Italy’s antitrust agency is investigating olive oil producers and ‘extra virgin’ varieties compared to other alternatives.
How the method works
Mérieux NutriSciences’ looked at more than 500 compounds which were determined, but only 63 of those allow differentiation between the different oils.
The firm said the method is a tool to ensure quality and authenticity for producers who buy some of their oils externally, for food manufacturers who make statements about the quality of olive oil in ready meals but also for retailers' private label products.
Bert Popping, chief scientific officer corporate food chemistry and molecular biology, said it was possible to differentiate between extra virgin and low quality oils, and based on the same profile, to determine origin of the oil, i.e. Spanish, Italian, Greek, California or a mix.
“We started to develop this method two years ago and collected samples from many different geographic locations. The reason is that olive oil was not only already identified by Friedrich Accum 195 years ago as adulterated product, but in 2013 a report from the European Commission, it was identified as the most frequently adulterated product,” he told FoodQualityNews.
“That was a very good reason for us to develop this novel authenticity test. The principle of this method can - and is - applied to other areas where products with a high risk of adulteration are concerned, e.g. certain milk-products.
“The method is hard to deceive because you would need to manipulate 63 parameters without knowing which ones the laboratory actually chose to build this profile. This is like playing the lottery and hoping to win.”
Popping said older and traditional methods usually assess only one or a handful of parameters and if fraudsters know the test principles, they can manipulate the samples.
“Without giving too many details away, this is best explained on the example of melamine. Here, the fraudsters knew that the protein content for milk was determined by a method called Kjeldahl," he said.
“This method determines the protein content by simply measuring the amount of nitrogen in the sample (nitrogen is contained in the amino acids which form the protein). The fraudsters worked out that a small molecule, containing many nitrogen atoms, would significantly raise the apparent protein content.
“So they added melamine to the milk protein. We all know what happened. Again, this is why a method that assesses so many parameters is difficult to cheat.”
Olive oil adulteration – how big of a problem?
David Neuman, master panel EVOO taster and CEO of Gaea North America, said all Virgin Olive Oils seeking to carry the name “extra virgin”, a legal definition, must meet standards both chemical and verified in a lab and sensory, verified by a taste panel.
“Extra virgin is the highest quality olive oil classification. It is olive oil that is 100% mechanically extracted, without chemicals or excessive heat, and should have no defects and a flavor of fresh olives,” he told us.
“In chemical terms extra virgin olive oil is described as having a free acidity, expressed as oleic acid, of not more than 0.8g per 100g. In order for an oil to qualify as “extra virgin” the oil must also pass both numerous chemical tests in a laboratory and a sensory evaluation by a trained taste panel. The olive oil must be found to be free from defects while exhibiting some fruitiness.
“The problem with this is that many companies are labelling their products as “Extra-Virgin” when they are in fact a lesser grade such as “Virgin” or "Lampante," or a blend of refined olive oil and extra virgin olive oil.”
Neuman is a trained panel taster accredited by the IOC (International Olive Council) and can legally evaluate olive oil as blindly presented to him as a member of a taste panel and look for defects and attributes and document their intensities.
He said every time tests are there are always mislabelled olive oils.
“Tom Mueller states in his book ‘Extra Virginity’ that 70% of all the extra virgin grade olive oils on the shelves in the US are mislabelled. It will take consumers to be fed up with the fraud to vote with their wallet and seek out better quality brands, like Gaea.”
Neumen said he trusts his nose first than mouth to determine if a product is extra virgin olive oil or not, adding colour, bottle shape and price are meaningless.
“If all buyers (trade and consumer) would at the very least smell oil out of a small glass and decide if it is pleasant and green and smells of fresh olives and then taste it and confirm what they smell, even if not trained they can be a pretty good judge of authenticity or fraud,” he said.
When asked what affect the accusations could have on industry, Neuman said it can vary with trade addicted to numbers so if no-one is challenging them, such as the USDA, lawsuits or vendors, they will continue to import, buy and sell fraudulent oils.
“They are cheap and sell well but that doesn’t make it right or legal. This has to start with the consumer boycotting the brands who were highlighted in the tests, then perhaps the trade will make a change.
“We do see some movement with buyers opting to sell better products. Kehe Food, the US’ largest speciality distributor has vastly reduced their selection of light and extra light olive oils, all of which are refined and the category manager there, Maria Reyes, has laid down the gauntlet and demands vendors present here with verifiable olive oils.”
Neumen said it is too early to comment on the 2015/16 harvest in the Northern Hemisphere and Greece has barely started but added the fraud in the news is nothing new and not related to this year’s harvest.
“I do know many producers in Italy and they pulled their fruit early (September-October) to offset the fears of another poor harvest. Those very green olives could be extremely high quality or very bitter.”