Dr. Gregory House was fond of saying, "Everybody lies." In the food industry, that maxim could be modified to, "Everybody cheats."
Indeed, food fraud is absolutely rampant. In some parts of the world, beef hot dogs may contain buffalo. Cheese labeled Parmigiano-Reggiano may not be authentic. Phony seafood is especially notorious. And now, new research indicates that extra-virgin olive oil (EVOO) may not be the pure, wholesome maiden you've been anticipating for your dinner night.
What Is Extra-Virgin Olive Oil (EVOO)?
Virgin olive oil is oil that has been extracted from olives via pressing and has not been processed in any way, such as by adding chemicals or heat. To be declared "extra-virgin," the oil must contain 1% oleic acid or less.
How much of the EVOO on grocery store shelves doesn't meet the definition of "extra-virgin"? About half. According to a report in Forbes, studies show 55% of the olive oil in the U.S. is phony, 46% in France, and 45% in Italy. In February of this year, Italian police busted the mafia for exporting fraudulent olive oil.
Science is now fighting back. In new a study, Tunisian researchers have used standard chemistry techniques to identify counterfeit olive oil.
Those who want to make a few extra bucks do so by adulterating EVOO with lower quality refined pomace olive oil (RPOO). While customers may be fooled, chemists are not.
The researchers adulterated EVOO with various amounts of RPOO. Then, they used gas chromatography (a standard method to identify and quantify molecules) to determine if they could discriminate between EVOO and EVOO adulterated with RPOO. Indeed, they could. In fact, they could detect as little as 1% contamination. (See chart.)
The column marked "0" indicates the molecular profile of pure EVOO. Columns marked "1", "2," etc. indicate 1 gram, 2 grams, etc. of added RPOO. Comparing Column 0 with Column 1 clearly indicates a statistically significant difference between the molecular profiles of pure EVOO and adulterated EVOO. The adulterated version contained elevated levels of sterols, waxes, and various types of alcohols. As the concentration of the adulterant increased, these telltale molecular fingerprints also increased.
It goes without saying that the food we are eating ought to match what's listed on the label. It appears as if chemists will be the enforcers who ensure the integrity of our food system.
Source: Hazem Jabeur, Malika Drira, Ahmed Rebai, and Mohamed Bouaziz. "Putative Markers of Adulteration of Higher-Grade Olive Oil with Less Expensive Pomace Olive Oil Identified by Gas Chromatography Combined with Chemometrics." J. Agric. Food Chem., 65 (26): 5375-5383. Published: 13-Jun-2017. DOI: 10.1021/acs.jafc.7b00687
MulderD on July 8th, 2017 at 16:09 UTC »
Between this and sushi, I'm really starting to wonder just how much of our food is mislabeled.
-supercow101- on July 8th, 2017 at 15:53 UTC »
Chemist here. Finally something I know about! Our company just started an olive oil panel to do sensory testing that instruments can't do. Turns out all my olive oil at home was garbage and I had no clue.
Smell your olive oil. Does it smell like crayons? It's gone rancid. Throw it the fuck out. Good olive oil usually smells like fresh cut grass or bananas (in our market, anyway.) Just go buy some new EVOO and smell it when you open it. Compare to crayon bottle. Youll see what i mean.
European markets with more variety smell like a whole lot of things, due to the differences in olive species and age of the olive at harvest. Young olives have a greener smell and taste, with higher kick of bitterness and pungentcy. More mature/ripe olives are slightly sweeter with a smoother finish. Both are good, it's a preference thing. Cooking with olive oil doesn't need fancy stuff (but not rancid will obviously taste better), we are talking about the type you'd want to use to make salad dressing or bread dips.
Edit: oh man, I wasn't prepared for this. I've literally taken lectures from pros to do this at work, it's hard to summarize. I'll find a good resource for anyone interested.
Edit 2: pretty good source. Just Google olive oil sensory testing and olive oil defects for more. https://www.oliveoiltimes.com/olive-oil-basics/good-olive-oils-gone-bad/8900
Here are some brands suggested by the olive oil association. http://blog.aboutoliveoil.org/21-olive-oil-brands-certified-for-authenticity
epz on July 8th, 2017 at 15:22 UTC »
Does anyone know of a brand of EVOO thats confirmed to be legit?