The use of methemoglobin complex in estimating cyanogen potential of cassava and cassava products

An improved method of analysis of cyanide in cassava and cassava products using methemoglobin complex is described. The cyanogen content of cassava mash, pre-fufu mash, fufu and Gari was determined spectrophotometrically. Optimal conditions were determined to be 24 h at 370C in phosphate buffer (0.05 M; pH 5.6). The average cyanogen content obtained were 14.68 ± 0.66, 13.49 ± 0.02, 11.94 ± 0.02 and 9.87 ± 0.64 mg/kg for cassava mash, pre-fufu, fufu and gari, respectively. The values estimated for cassava mash and pre-fufu are greater than the values obtained for the processed fufu and gari, and also greater than the WHO safe value for cassava flour (10 mg/kg). The fact that the results of this work gave lower values of cyanide in processed cassava products compared with the value of unprocessed cassava suggests the validity of this method.