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If you've been reaching for chips, mayonnaise or salad dressing labeled "made with avocado oil," there's a good chance the oil inside isn't pure avocado oil, despite it being the only listed oil ingredient. University of California, Davis, researchers tested processed foods marketed as containing avocado oil. They found 48 of the 54 avocado oil-labeled products were adulterated with cheaper oils. The was published in Applied Food Research. 

Researchers purchased the products in 2025 and 2026 from online retailers and California stores. They represent only a portion of the avocado oil processed food market.

"Consumers are increasingly paying a premium for products made with avocado oil or olive oil,” said lead author , Professor of Cooperative Extension in the 51�ԹϺ��� Davis Department of Food Science and Technology. "They deserve to get what they pay for and food manufacturers deserve confidence that the ingredients they purchase from suppliers are authentic."

Researchers found that of the products tested, 93% of chips, 71% of mayonnaises and 100% of salad dressings labeled as authentic avocado oil contained other oils. By contrast, when researchers applied the same purity tests to 20 olive oil-labeled processed foods, only one failed. 

The gap between avocado and olive oil results reflects the fact that olive oil authenticity has been studied, tested and scrutinized for decades. Avocado oil is a relatively new and expensive product category and has not been monitored at the same level. As a result, consumers have less protection against misleading labels.

This is the latest in a series of 51�ԹϺ��� Davis findings on the authenticity of avocado oil. A 2020 study found 82% of commercial bottled avocado oil were either rancid or mixed with other oils. A later study found 70% of private label oils were rancid or adulterated.

Detecting adulterated oil in processed foods

Researchers measure fatty acids and sterols — chemical “fingerprints” unique to each oil — to verify authenticity.  One potential concern is that processing, such as deep frying, blending or emulsifying, can change those chemical fingerprints. Wang’s team tested that directly and found fatty acids and sterols changed minimally. The study also used conservative criteria when evaluating authenticity. 

“In our experience we’ve noticed natural variables, such as geographic origin and avocado variety, can change these fingerprints,” said Wang. “So we gave the samples some wiggle room, giving them a 10% margin of deviation to account for that, but 89% of the avocado products still failed.”

Suppliers may be source of avocado oil adulteration

Wang said brands whose products failed may not know they are using adulterated oil. Many food companies source their oils from third-party brokers or from several different suppliers. Without rigorous testing, food companies may never detect adulterated oil. Wang said the adulteration likely originates with oil suppliers.

"If consumers are buying potato chips that say they’re made with 100% avocado oil, that should be the product that they're getting,” noted Wang. “I don't think there is enough accountability throughout the supply chain. Suppliers of adulterated oil may be hiding behind a couple of layers of supply chain, making it difficult to identify where the problem originated.” 

Wang said at the same time, food companies could do more to monitor and verify the authenticity of the oil they purchase.

Consumers face the same outcome either way: They pay premium prices for products that aren’t what they claim to be. Avocado oil products in the study were priced comparably to olive oil products or higher — yet olive oil products were overwhelmingly pure while avocado oil products were overwhelmingly not.

Why consumers pay a premium

Grocery stores now stock far more avocado oil products than they did just a few years ago. Chips, mayonnaise and salad dressings "made with avocado oil" now occupy prime real estate in major grocery chains, marketed in many cases to consumers who are intentionally trying to avoid other oils. Wang's data suggests most of those consumers are not getting what they pay for.

Other authors of the study include Natalie Lopez-Alvarez, Xueqi Li and Benjamin Vizgordiski. The study received no outside funding.