The Transparency Redesign: Study Finds 90% of Processed Foods Labeled With Avocado Oil Are Adulterated

Shoppers paying a premium for chips, mayonnaise, and salad dressings made with avocado oil are likely getting cheap seed oils instead. A new study from the University of California, Davis, reveals that 89 percent of processed foods claiming to use avocado oil are adulterated.

The research, published in the journal Applied Food Research in July 2026, tested 54 products purchased from online retailers and California stores. The failure rates across the board were staggering: 93 percent of chips, 71 percent of mayonnaises, and 100 percent of salad dressings failed authenticity tests, indicating widespread fraud in a rapidly growing grocery category.[1][3][5]

To determine authenticity, researchers extracted the oils from the products and analyzed their fatty acids and sterols. These components act as chemical fingerprints unique to each type of edible oil. The team compared these profiles against established international reference ranges for real avocado oil.

Recognizing that agricultural products vary, the researchers allowed a generous 10 percent margin for natural variation between different avocado varieties and growing regions. A product only failed the test if its chemical makeup fell entirely outside that broad tolerance, ensuring that minor natural discrepancies were not flagged as adulteration.[1][5]

Despite the conservative testing criteria, the vast majority of products failed. "If you're buying avocado oil products, it's very likely that you're not getting what you're paying for," said lead author Selina Wang, a professor of food science at UC Davis who has studied oil fraud for years.

The deviations were not subtle. In some cases, the chemical fingerprint of the extracted oil matched soybean oil almost entirely, with essentially no authentic avocado oil detectable in the product. The data suggests that many brands are quietly substituting premium ingredients with the exact seed oils their customers are trying to avoid.[2][4]

Anticipating pushback from the food industry, the researchers also ruled out the possibility that the manufacturing process itself caused the chemical changes. Frying a potato chip at high heat or emulsifying oil into mayonnaise can alter an oil's structure, prompting questions about whether the testing methodology was flawed.

By conducting their own controlled frying and emulsification experiments in the laboratory using pure reference oils, the team confirmed that the authenticity markers remained largely unchanged. The cheaper oil was definitively present in the mixture before the products were ever cooked or blended on the production line.[3][5]

The motive for this widespread adulteration is purely economic. Pure conventional avocado oil currently costs between $4 and $5 per pound on the wholesale market. In contrast, commodity seed oils like soybean, canola, or sunflower oil cost just $0.50 to $1.50 per pound.

Swapping in cheaper oils allows manufacturers to maintain a premium retail price on the shelf while drastically cutting their production costs. The U.S. Food and Drug Administration explicitly lists avocado oil as one of the foods most frequently targeted for economically motivated adulteration, a practice where a premium ingredient is quietly diluted to boost profit margins.[6]

The problem appears uniquely concentrated within the avocado oil supply chain. As a control group, the UC Davis team applied the exact same purity tests to 20 processed foods labeled as being made with olive oil. The results were drastically different: only one olive oil product failed the authenticity check.

Researchers attribute this stark contrast to the decades of regulatory scrutiny and strict international standards applied to the olive oil industry. Following high-profile scandals in the early 2000s, the olive oil sector developed rigorous testing infrastructure and supply chain oversight that simply does not exist yet for avocado oil.[1][2][5]

Avocado oil is a relatively new premium ingredient, and it currently lacks enforceable federal purity standards in the United States. There are no strict legal definitions dictating exactly what chemical profile a product must meet to be labeled as avocado oil.

This regulatory vacuum leaves the door open for suppliers to cut their products with cheaper alternatives without facing immediate legal consequences. Wang noted that many food brands purchase their oils through third-party brokers and may not even realize they are using adulterated ingredients, highlighting a severe lack of accountability throughout the supply chain.[3][4]

This is not the first time UC Davis has exposed fraud in the avocado oil market. Previous studies conducted by Wang's laboratory in 2020 and 2023 found that the vast majority of commercially bottled avocado oils sold in the United States were either rancid or adulterated with other oils.

Those earlier findings sparked multiple class-action lawsuits against retail brands. The new 2026 findings confirm that the issue has not been resolved; instead, the fraud has simply expanded deep into the processed food sector, where the oil is hidden within complex ingredient lists.[1][6]

For consumers, the findings are deeply frustrating. Many shoppers specifically seek out avocado oil products to avoid seed oils, paying a significant markup in the process. The study found that products marketed with premium oils generally commanded higher retail prices than comparable products made with standard vegetable oils, yet that higher price tag offered no guarantee of authenticity. Until stronger verification protocols and lot-level supply chain accountability are established across the industry, consumers buying avocado oil snacks and condiments are largely flying blind in the grocery aisle.[2][3][4]