Food scientists call for the FDA to set appropriate standards for avocado oil as their study reveals shockingly high levels of confusions and adulteration.
Researchers said that the majority of avocado oil sold in the US is low-quality, misleading or adulterated with other oils. University of California (UC), Davis.
Called the nation’s first comprehensive study of the quality and purity of commercial avocado oil, the UC Davis team reports that 82 percent of test samples were either rancid before their use or mixed with other oils.
Researchers found that in three cases, the bottles are labeled as ‘pure’ or ‘extra virgin’ avocado oil, which contains about 100 percent soybean oil.
“I was surprised that there was no avocado oil in some samples,” said Selina Wang, a cooperative extension specialist in the Department of Food Science and Technology, a cooperative extension specialist in the Department of Food Science and Technology who led the study. “Most people who buy avocado oil are interested in health benefits as well as a mild, fresh taste, and are willing to pay more for the product.”
Wang suggested that “no standards” were responsible for such shocking results. He said that there is no regulation that can determine whether an avocado oil is of quality and purity.
According to the researchers, avocado oil is relatively new, with the Food and Drug Administration (FDA) yet to adopt standards of identification, i.e. basic food standards designed to protect consumers from misleading labels and adulterated goods.
“These findings highlight the urgent need for standards to protect consumers and establish a level playing field to support the continued growth of the avocado oil industry.”
Wang and Hillary Green, PhD candidates at Wang’s Lab, analyzed the serious chemical parameters of 22 domestic and imported avocado oil samples, including all the brands they could find in local shops and online.
“In addition to testing for commercial brands, we also purchased avocados and extracted our oil in the lab, so we would know, chemically, what pure avocado oil looks like,” Wang said.
Test samples included oils of various prices, some written ‘extra virgin’ or ‘refined’. Virgin oil means extracted from fresh fruit using only mechanical means, while refined oil is processed with heat or chemicals to remove impurities.
Fifteen samples were oxidized before the expiration date. The oil loses its flavor and health benefits when oxidized, which occurs over time and when exposed to too much light, heat, or air. Six samples were mixed with large amounts of other oils including sunflower, safflower and soybean oil.
The UC Davis team found that only two brands produced samples that were pure and non-toxic. Those Chosen Foods and Marianne’s Avocado Oil, both were refined avocado oils made in Mexico. Among the virgin grades, Calpur produced in California was purer and fresher than other samples in the same grade according to researchers.
In terms of products without currently applicable standards, avocado oil is not alone, researchers say, pointing to honey, spices and ground coffee as prime examples.
Wang is now working to develop faster, better and cheaper chemical methods to detect adulteration. She hopes that this will provide a reliable way for bulk buyers to test avocado oil before selling it.
She is also evaluating more samples to see how time and storage affect quality, and performing shelf-life studies to encourage FDA officials to establish appropriate standards for avocado oil .
Wang has a history of exposing low-grade foods; 10 years ago he came to know that the extra virgin olive oil sold in the US was of very low quality. His research sparked a cascade of reactions, which set California one of the world’s most stringent standards for various grades of olive oil. The FDA is now working with importers and domestic producers to develop identified standards for olive oil.
“Consumers who seek the health benefits of avocado oil deserve to get what they think they are buying,” Wang said. “Working closely with the industry, we can set standards and ensure that customers are receiving high-quality, authentic avocado oil and companies are competing on a level playing field.”
What to see …
- The flavor of avocado oil varies depending on the variety and region, but in general, authentic, fresh virgin avocado oil tastes of grass and butter. Researchers have compared it to mushrooms.
- Virgin avocado oil should be green. Refined avocado should be light yellow and almost clean.
- Even good oil gets stale over time. It is important to purchase an appropriate size that can be finished before oxidation of the oil. Keep oil away from light and heat. A cool, dark cabinet next to the stove is a good choice.
- When stale, oil will start to smell rancid.
- For fresh oil, buy the one that is closest to the time of harvest / production.
- The best-before date is not always a reliable indicator of quality and varies from the date of use.