Study rings alarm on avocado oil, finds 82% expired or adulterated

According to the report, recently published in the journal Food Control​, this is the country's first extensive study of commercial avocado oil quality and purity. 

The demand for avocado oil is growing, and so are calls for standards. New research out of the University of California, Davis, found that the majority of avocado oil sold in the United States is of poor quality, mislabeled or adulterated.

A new study analyzed avocado oils currently on the market in the US to evaluate their quality and purity. The results revealed that the vast majority of commercial samples were oxidized before reaching the expiration date on the bottle. 

The study

A total of 22 avocado samples consisting of both extra virgin and refined oils were collected from six grocery stores (14 samples) and two online sources (eight samples). Each oil sample was wrapped in aluminum foil and stored in the dark at 20 °C. Samples were purged with nitrogen after each opening. Samples were separated into three groups according to their label: extra virgin oil, refined avocado oil, and unspecified oils, which were samples that either did not specify the type of avocado oil or had ambiguous labels on the bottle.

Findings

Overall, UC Davis researchers report that at least 82% of test samples were either stale before expiration date or mixed with other oils. Fifteen of the samples were found to be oxidized before the expiration date, which causes oil to lose its flavor and health benefits. 

“This study demonstrates, for the first time, there are problems in both quality and purity in the store-bought extra virgin and refined avocado oil,”​ the authors noted, adding that this is likely a result of improper or prolonged storage, using damaged or rotten fruits, or extreme and harsh processing conditions. 

Six samples were found to be adulterated with other oils, including sunflower, safflower and soybean oil. In three cases, the food scientists confirmed adulterated levels near 100% in two “extra virgin” and one “refined” sample. 

Just two brands produced samples that were pure and non-oxidized: Chosen Foods and Marianne's Avocado Oil, both refined avocado oils made in Mexico. 

CalPure, produced in California, was found to be more pure and fresher compared to the other samples in the virgin grade.

Stefan Gafner, PhD, Chief Science Officer, American Botanical Council (ABC) told Nutraingredients-USA​ that avocado oil costs more than most of the commonly used cooking oils. “So there is a financial incentive to dilute it with lower-cost vegetable oils such as soybean oil, which was mentioned in the study. I checked the pricing of some of the commercially available oils online, and it’s difficult to believe that authentic good quality avocado oil can be sold below US $10/gallon, which is what some products claiming to be avocado oil are sold for.”​

The urgent need for standards 

Selina Wang, Cooperative Extension specialist in the Department of Food Science and Technology, who led the study, said “Because 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. 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."​

Gafner stated that since avocado oil is still the new kid on the block when compared to sunflower, peanut, or olive oils, the Food and Drug Administration has not yet adopted a standard of identity. These standards protect consumers from buying adulterated products, and without them, FDA has no authority to regulate avocado oil quality and authenticity.

“I agree that there is an urgent need to develop industry standards,”​ said Gafner. “Such standards have been developed for other oils (including olive oil, which is the subject of a laboratory guidance document being written by the ABC-AHP-NCNPR Botanical Adulterants Prevention Program), and there is no reason that the analytical methods used to establish the quality and authenticity for these other oils can’t be applied to avocado oil. Unfortunately, the science sometimes is a bit slow to catch up with marketing, but I expect that the responsible members of the industry will find common ground on avocado standards relatively quickly.”​

Source: Food Control​

Volume 116, October 2020, doi.org/10.1016/j.foodcont.2020.107328​

“First report on quality and purity evaluations of avocado oil sold in the US”​

Author: H. Green et al.