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A simple home experiment using water and palm oil has gone viral across Nigerian social media, prompting concerns among food safety specialists about its reliability as a method to detect dye adulteration in cooking oil.
The trend was launched by Chinonso Egemba, a Nigerian medical doctor and health influencer widely known as Aproko Doctor, who posted a demonstration video on his Instagram page in December 2025. The clip has since circulated widely on TikTok and Instagram, with users recording their own results and sharing them online.
The procedure is straightforward. A transparent glass cup is filled with palm oil, then water is added. Some users reverse the order, pouring water first and oil afterwards. According to proponents, the outcome is self-evident: if the water becomes stained, the oil has been mixed with dye; if the two liquids separate cleanly, with water settling at the bottom and oil floating on top, the oil is considered pure.
Adulteration of palm oil is a long-standing problem in Nigeria, where the National Agency for Food and Drug Administration and Control (NAFDAC) has struggled to prevent the circulation of contaminated products in food markets. Health practitioners have warned that some of the dyes used in such practices may be carcinogenic. The issue resurfaced online after an old video showing a large quantity of dye being mixed into palm oil gained renewed attention, prompting consumers to look for ways to test their oil at home.
Supporters of the test, including Aproko Doctor and other health commentators, frame the logic as 'basic chemistry.' Genuine palm oil derives its characteristic red-orange colour from carotenoids, naturally occurring fat-soluble pigments that do not dissolve in water. Because oil and water have different chemical properties, they do not mix, and any added water-soluble dye would, in theory, bleed into the water layer.
The argument, however, does not hold up under closer scientific scrutiny. According to the National Institutes of Health, palm oil's natural pigments, particularly carotenoids, are indeed fat-soluble and do not readily dissolve in water. Yet some artificial dyes are also oil-soluble, meaning they remain in the oil phase and do not leach into water. Conversely, water-soluble coloured substances or other contaminants could colour the water even when no dye has been added to the oil.
Racheal Hungbeme, a food scientist based in Nigeria, told DUBAWA that the viral test is not a reliable method for verifying palm oil adulteration. 'Gas chromatography is an effective way to check the authenticity of oil,' she said, explaining that the laboratory technique vaporises a sample and passes it through a carrier gas to separate and identify its components. She noted that colour migration into water depends on the chemical properties of the colouring substance, not on whether the oil is naturally coloured or artificially dyed.
Chika Okegbe, another food safety expert, was equally direct. She explained that a water test cannot determine whether palm oil has been dyed, noting that palm oil can be adulterated with different substances, including Sudan dyes, which are lipophilic, or oil-loving, and dissolve in oil rather than water. 'So if your palm oil contains Sudan IV, adding water will not pull the dye out of the oil. It can give a false negative,' she said.
Detecting synthetic dyes in palm oil requires laboratory analysis rather than a visual test. Scientific studies have used thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), liquid chromatography coupled with diode-array detection (LC-DAD), and mass spectrometry to identify Sudan dyes and other synthetic colourants in edible oils. A 2024 review of reported Sudan-dye adulteration in palm oil relied on HPLC and other chromatographic techniques to detect the dyes, while researchers have also investigated faster screening approaches such as near-infrared spectroscopy and surface-enhanced Raman spectroscopy.
These methods differ fundamentally from the viral water test, which relies solely on whether visible colour appears to move from the oil into the water. While the home experiment may appear simple, experts agree it cannot reliably tell consumers whether their oil contains added dye, since the transfer of colour depends on the chemical properties of the substance involved and does not provide sufficient evidence to confirm or rule out adulteration.
Source: Dubawa