Oil authenticity: testing, regulations and shortfalls

Edible oils are widely consumed and used in many product formulations, due to their nutritional benefits, pleasant flavour and functional properties. However, edible oil adulteration is a major food fraud issue. There are regulations in place which protect consumers from being misled, and those include protection from fraudulent activities; but where do the regulations fall short?

Edible oil adulteration is a major food fraud issue. Oils of poorer quality or from alternate sources can easily be blended into high-cost oils, which are then sold at lower prices than the authentic products. This is possible because of the physical similarities between different oils.

Acts of adulteration may have negative health impacts, in addition to being unethical. Coconut oil, for example, may be adulterated with paraffin oil, which is extremely hazardous to human health. However, it is more common for edible oils to be adulterated with other edible oils.

Olive oil, for example, is reported to be one of the most adulterated food products in the world. While less than 10% of world olive oil production meets the criteria for labelling as extra-virgin, it has been estimated that up to 50% of olive oil retailed is labelled extra-virgin. Olive oil may be diluted with cheaper olive oils or other vegetable oils, which ultimately affects the quality, nutritional value and commercial value of the product.

Testing for adulteration

Oils can be analysed for quality and authenticity. A simple test to determine whether an oil has been adulterated is fatty acid profiling (also known as fatty acid methyl esters or ‘FAME’ analysis). To confirm authenticity, the results of this analysis can be compared to the fatty acid profile as described by the relevant regulation.

Routine oil authenticity testing should form an important part of any oil supply chain, as the test results provide critical assistance in valuing oils for the marketplace.

Regulatory background

In the South African regulatory framework, a draft regulation regarding the Grading, Packing and Marking of Edible Vegetable Oils was published in November 2016 under the scope of the Agricultural Product Standards (APS) Act, overseen by the Department of Agriculture, Land Reform and Rural Development (DALRRD). Subsequent to the first draft, there have been no further drafts or regulations published regarding edible oils.

In the absence of local regulations for a specific product, as a guide one can turn to the standards set by Codex Alimentarius for such products.

Codex has a standard for olive oils and olive pomace oils (CODEX STAN 33 – 1981), as well as a standard for named vegetable oils (CXS 210-1999), which includes specifications for the following oils:

What about avocado oil?

The demand for avocado oil has increased significantly in recent years, as its noteworthy health properties have resonated with consumers. Avocado oil has high unsaturated fatty acid content and is rich in vitamin E, ascorbic acid, vitamin B6, ß-carotene and potassium. However, there is currently a lack of enforceable standards governing the quality and authenticity of avocado oil. The Codex standard for named vegetable oils (CXS 210-1999) does not include avocado oil, and there are no other internationally defined parameters for avocado oil.

This regulatory absence may be a motivating factor for fraudulent activities. A recent US study found two ‘extra-virgin’ samples and one ‘refined’ sample of avocado oil to be adulterated with soya bean oil at levels near 100% (Green & Wang, 2020). There is clearly an urgent need to develop standards for avocado oil – not only to protect consumers, but also to establish a level playing field in support of the continuing growth of the global avocado oil industry.

Although there are no set standards for avocado oil, the scientific community has published many peer-reviewed papers on the composition of the common fatty acids of avocado oil. These findings can be used to interpret FAME test results and determine if an avocado oil sample has been adulterated.

In light of the Consumer Protection Act (Act 68 of 2008), which states that consumers have a right to high-quality products that are not falsely marketed or misrepresented, routine screenings should form an important part of the avocado oil supply chain to ensure that authentic products are being sold.

If you are interested in testing the authenticity of an oil sample, require regulatory advice, or would like to know more on this topic, please contact us.