A recent study from a group of researchers at the Kwame Nkrumah University of Science and Technology (KNUST) has disclosed that powdered turmeric products sold in Greater Accra markets lack quality.
The research by Biochemistry and Biotechnology Department’s uncovered chalk and Metanil yellow, an unapproved food colorant, in samples of Turmeric powder sourced from ten different markets, including Agbogboloshie and Malata.
The study highlighted a troubling trend of food adulteration, with all twenty turmeric products examined found to contain Metanil yellow, an azo dye, while two samples contained chalk.
Per research the long-term exposure to these chemicals can lead to severe health risks, including liver cancer, cardiovascular diseases, peptic ulcers, and kidney issues.
Turmeric which is praised for its numerous health benefits is widely used in Ghanaian households not only as a spice but also as a food preservative and colourant.
It is recognized for its effectiveness in treating ailments such as diabetic wounds, hepatic disorders, rheumatism, and coughs.
The primary active ingredient, curcumin, contributes to turmeric’s vibrant yellow color and its nutritional and medicinal properties.
An Associate Professor of Biochemistry, Prof. Christopher Larbie, who led the team that conducted this study, shed light on the practice of vendors adding chalk to increase the quantity and enhance the yellow hue of turmeric powder.
“What we gathered was that they add the chalk to increase the quantity of the turmeric and also enhance the yellow colouration of the vegetable,” he said.
The study, published in the European Journal of Nutrition & Food Safety, found that freshly sourced turmeric powders are typically rich in B vitamins and Vitamin C, which play essential roles in metabolism and carbohydrate digestion.
However, the researchers noted a significant reduction in these nutrients, approximately a 72% decrease in curcumin content, with Vitamins B1 and B2 declining by about 90% and 92% respectively. Alarmingly, Vitamin C levels were found to be zero in some samples.
“The Vitamins B1 and B2 had decreased about 90% and 92% respectively. Vitamin C was zero. When you buy such products, you are not getting the actual nutrients you need for disease prevention and healing,” Prof Larbie added.
The researchers attributed the loss of vitamins to prolonged exposure to air, which alters their chemical composition, especially as these vitamins are heat-sensitive.
While the study did not quantify the levels of contaminants detected, it emphasized the need for increased public awareness regarding food safety.
Food adulteration poses significant risks to health, potentially leading to symptoms such as diarrhoea, dysentery, and vomiting.
The toxic effects of Metanil yellow, in particular, can impact the liver, brain, and reproductive systems, and it has not been approved as a food colorant in Ghana.
To combat this issue, the scientists have recommended regular food surveillance.
The study advised that consumers check for turmeric adulteration by dissolving the powder in water; a delayed dissolution may indicate the presence of chalk.
Additionally, it stated that if the powder leaves a yellow stain on the tongue, it may suggest contamination with Metanil yellow.
“Metanil yellow is toxic on the liver, brain, and reproductive systems. It has negative effects on some of the brain hormones. Metanil yellow hasn’t been approved as a food colour in Ghana,” Prof. Larbie said.
