The fact that most olive oils on the market are fraudulently diluted with less expensive (and more harmful) oils has been known for years. Now, a report1,2,3 in the journal Food Control warns that the purity and quality of avocado oil sold in the U.S. is questionable at best, and that standards to protect consumers and genuine producers are urgently needed.
Adulterated Avocado Oil Is Commonplace
According to the Food Control report,4 a vast majority of commercially available avocado oils labeled as “extra virgin” and “refined” are in fact adulterated and of poor quality; 82% were found to have gone rancid before their expiration date.5
Three of 22 oils were not even avocado oil but something else entirely (likely soybean oil). Co-author Selina Wang told Olive Oil Times6 that while she expected “some percentage of adulterants,” she was shocked to find several cases of 100% adulteration. As noted in the report:7
“This study analyzed avocado oils currently on the market in the US to evaluate their quality (e.g., free fatty acidity, peroxide value, UV absorbances, vitamin E) and purity (e.g., fatty acids, sterols, triacylglycerols).
Our results showed that the majority of commercial samples were oxidized before reaching the expiration date listed on the bottle. In addition, adulteration with soybean oil at levels near 100% was confirmed in two ‘extra virgin’ and one ‘refined’ sample.”
How Purity and Quality Are Assessed
As explained in the Food Control report,8 an oil is considered authentic and pure when no additives or other oils have been added, and when the content matches that listed on the label.
Quality includes consideration of the raw material (the quality of the avocado used), the extraction process used and storage, but is “mostly related to the level of hydrolysis of the fruit and oxidation of the oil.” With this report, the authors have begun compiling a database “to support standards development for this industry.”
In all, 22 avocado oil samples were obtained from six grocery stores and two online sources, covering the major brands and types of oils, which include extra virgin/unrefined and refined. Countries of origin included California, Mexico, Brazil and Spain.
While previous researchers have proposed a healthy level of free fatty acidity (FFA) should be between 0.1% and 0.55% for refined avocado oils, three of the 22 samples had FFA values close to 2.5%. Extra virgin avocado oils had an FFA range between 0.03% and 2.69%, with an overall average of 1.31%.
According to the authors, these elevated FFA levels may be due to poor-quality fruit and/or poor handling during processing.9
“Unhealthy fruits that are damaged, bruised, overripe, insect infested; prolonged time between harvest and processing; overheating during processing are all factors that can contribute to a rise in FFA,” the authors note.
To put this into an easier to understand perspective for you, I am sure you have opened an overripe avocado in the past to see the ripe green avocado color turn to very dark, nearly black. Can you imagine the entire avocado being black when you open it up and processing it and turning it into oil? Well, that is precisely what you do when you purchase rancid avocado oil.