Influence of cultivars and processing methods on the cyanide contents of cassava (Manihot esculenta Crantz) and its traditional food products

Abstract

Cyanide is a toxic substance found in several plants roots amongst which cassava. The objectives of this study were to quantify cyanide contents in the roots of the main cassava varieties cultivated in Cameroon and evaluate the effect of some traditional cassava processing methods on their initial contents. Ten local and ten improved varieties of cassava samples were collected in the locality of Mbankomo, Ongot village, Centre region. These roots were processed into traditional foods: “Chips”, “Gari” and “Fufu”. The cyanide content was determined in the parenchyma, cortex, and cassava derived foods. Local varieties had cyanide contents varying from 79.34±3.58 to 181.33±0.48 ppm, while contents in improved varieties varied from 61.03±9.44 to 118.04±7.16 ppm. Cyanide content quantitative classification revealed that studied cassava varieties fell within the range “moderately” to “highly” toxic. Results showed no clear link between morphological characteristic and cyanide contents of the studied cassava varieties. Although cyanide contents were higher in the cortex varying from 117.80±11.32 to 210.07±9.15 ppm for local, and from 98.43±15.49 to 155.44±12.11 ppm for improved varieties. Processing of cassava into different traditional foods contributed to reduce cyanide content. Elimination rates were as a function of the process involved: 47%, 80% and 91%, respectively, for “Chips”, “Gari” and “Fufu”. Cassava processing reduce cyanide content, however extent of reduction varies from one product to another. Keywords: Cyanide, Cassava cultivars, Traditional processing, Detoxification