Assessment of Cyanide Content in Cassava (Manihot esculenta Crantz) Varieties and Derived Products from Senegal

Abstract

We investigated cyanide levels in four cassava varieties and some derived products from Senegal. The study was conducted on fresh tubers by sampling in three longitudinal positions (1/4; 1/2; 3/4) and four radials (A, B, C and D). In addition, the sampling of derived products was carried out by product types (chip dried, graded, unpressed and pressed attieke, gari and flour). Cyanide contents were determined using differential pulse polarography. Results showed that whatever the variety considered, there was no significant difference between the total HCN content in cassava slices (1/4; 1/2; 3/4). Similarly, results from different layers (A, B, C and D) did not highlight the radial variability of the total HCN content. We showed a variable cyanide content (mg HCN/kg fresh material) in cassava varieties: 104.3 ± 3.9; 171.6 ± 5.4; 231.2 ± 10.2; 270.8 ± 12.0 for Kombo, Nigeria, Soya and Gniargui respectively. The detoxification processes (attieke, gari and flour) indicated a reduction rate in excess of 80% and may be effective to reduce the cyanide content in cassava root down to a tolerable level (< 50 mg/kg).