Toxicological Assessment of Cyanide Content in Garri on Drosophila Melanogaster

Garri, produced from the roots of cassava (Manihot esculenta Crantz), is a widely consumed staple food that plays a vital role in reducing food insecurity in Nigeria. Despite its nutritional value, garri has been reported to contain residual cyanide, which poses potential health risks to humans. This study investigated the toxicological effect of cyanide in garri using Drosophila melanogaster (fruit flies) as the experimental model. The objective was to assess the influence of garri extract supplementation on the survival rate of Drosophila melanogaster.Cyanide levels in three garri samples were quantified using the picrate method. The samples were obtained from different markets in Edo State, Nigeria: yellow garri (Sample A) from Ekiosa Market, Oredo Local Government Area (21.13 µg/ml), deep yellow garri (Sample B) from New Benin Market, Ikpoba-Okha Local Government Area (12.19 µg/ml), and white garri (Sample C) from Uselu Market, Egor Local Government Area (24.52 µg/ml). Among these, Sample B was selected for the survival assay. For the experiment, flies were exposed to diets containing different concentrations of garri extract mixed with cornmeal for 21 days, with the diets renewed every five days. Mortality was recorded daily to determine survival rates. Three treatment groups received garri extract at concentrations of 1 g/100 ml (2.466 µg/ml cyanide), 10 g/100 ml (12.537 µg/ml cyanide), and 100 g/100 ml (36.613 µg/ml cyanide), respectively, while a control group received no garri extract. Each vial contained 30 flies, and 200 µl of each treatment was incorporated into the drosophila meal. Results showed that the control group exhibited the highest survival rate (79%), followed by flies exposed to 1 g/100 ml (63.3%), 10 g/100 ml (54.3%), and 100 g/100 ml (46.6%) garri extracts. These findings indicate that garri consumption, due to its residual cyanide content, negatively affects the survival of Drosophila melanogaster. Therefore, proper monitoring of cassava processing methods is essential to minimize cyanide concentration in garri and to promote public awareness regarding its potential health hazards.