Adulteration scandals in the olive oil industry have been increasingly explored by the public in the last 10 years. As a result, consumers have looked for a dependable “at-home” test to ensure that their Extra Virgin Olive Oil is 100%.
Many have heard of the “refrigerator test”, where a bottle of Extra Virgin Olive Oil is placed in the fridge to see if it solidifies and becomes cloudy. This test has been suggested in the past as a good indicator to determine if a bottle of Extra Virgin is 100%-- if it solidifies, this is supposed to indicate that the oil is, in fact, 100% EVOO. If it remains liquid, this suggests adulteration.
This theory has developed because of the chemical profiles in monounsaturated and polyunsaturated fats. Oils high in monounsaturated fats (like Extra Virgin Olive Oil) typically solidify below 39.2˚ F (4˚ C). On the other hand, oils high in polyunsaturated fats (like Sunflower Oil) solidify in temperatures below -22˚ F (-30˚ C). Therefore, It is suggested that if a monounsaturated fat like EVOO doesn’t solidify in the fridge, then it must be adulterated with a polyunsaturated fat that prefers to remain in a liquid state. This premise has recently been proven inaccurate.
Olive Oil tasting expert Richard Gawel recently called this test a “myth” in his blog. This is because there are only a few oils that are very high in only monounsaturated or polyunsaturated fats like the examples above. In reality, most oils are comprised of a bit of both: for example, both Peanut and Canola Oil both contain 50-60% of the monounsaturated fat, and can also solidify in the fridge.
The UC Davis Olive Center recently evaluated this Fridge Test, and also found that it was an unreliable indicator of olive oil quality. In their findings, it was clear that if Extra Virgin Olive Oil had been mislabeled and mixed with up to 50% of a lesser olive oil grade (or even 10% of a cheaper oil like Canola) it may still solidify in the fridge. Many of their adulterated samples passed the supposed “fridge test”, proving the theory inaccurate.
To ensure an authentic product, a buyer should receive Certificates of Analysis with each order that will display the chemical findings from authenticity lab testing. It’s also smart to do a sample test analysis by QA/R&D (especially before a direct flexitank shipment). Most of all, it’s very important to have a strong, trustworthy relationship with your supplier.
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Topics: Industry Trends, Quality Control