Avocados, touted as the cure-all superfood, are also pressed to make an oil full of a healthy fat called oleic acid. It is used as a cooking oil and can be sprinkled on food. It is also used for its moisturizing properties in various cosmetic products.

According to a new study published in the journal Food Control, most avocado oils tested by researchers expired early, were mixed with other oils and labeled inaccurately as “extra virgin oil."

A study of avocado oil quality was led by Selina Wang, cooperative extension specialist, department of food science and technology at the University of California, Davis. Along with PhD candidate Hilary Green, Wang categorized oil samples based on origin, cost, packaging and purchasing method.

“...There are no standards to determine if an avocado oil is of the quality and purity advertised, no one is regulating false or misleading labels," said Wang. "These findings highlight the urgent need for standards to protect consumers and establish a level playing field to support the continuing growth of the avocado oil industry,” she said in the news release.

The oils were sorted and coded according to the type of oil: extra virgin oil, refined oil and unspecified oils.

The researchers collected 14 samples from six grocery stores and eight samples from online stores. Of the 22 samples acquired from all the major brands sourced from California, Mexico, Brazil and Spain, about 82 percent turned rancid before the expiration date printed on the label and were also mixed together with different oils. Specifically, the researchers discovered that three bottles had more soybean oil than avocado oil, despite being labeled “pure” and “extra virgin.”

Avocado
A farmer harvests avocados at an orchard in the municipality of Uruapan, Michoacan State, Mexico, on October 19, 2016. Ronaldo Schemidt/AFP/Getty Images

Higher pricing did not make a difference to quality either. The most expensive avocado oils in the review had the highest peroxidation value.

Some of the other findings include:

  • 15 samples expired before their due date because of oxidation and heat or light exposure.
  • Six samples were diluted with sunflower, safflower and soybean oils.
  • Refined avocado oils by Chosen Foods, Marianne’s Avocado Oil and CalPure appear pure and safe to consume.
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