Cyanogenic potential of selected cassava varieties in Zombo District, Uganda

Abstract

Both improved and local cassava varieties are widely grown and also, consumed in Zombo district as well as West Nile Sub region and Uganda as a whole. However, all cassava varieties contain cyanogenic glycosides which are toxic, although the amounts in each cultivar may vary considerably. Consumption of such toxins in sufficient quantities poses a health risk since they can cause acute cyanide poisoning and death in humans and animals. As such, information concerning the cyanogenic glycosides content in cassava cultivars is indispensable in averting health risks linked with cassava consumption. In this study, the cyanogenic content of the most common local cassava varieties (Bisimwenge, Nyar-anderiano, Nya-matia, Nya-pamitu, Nya-papoga and Nyar-udota) grown in Zombo district and six improved cassava varieties (NASE 3, NASE 9, NASE 14, NASE 19, TME 14 and TME 204) were investigated. Generally, the improved cassava varieties revealed lower levels (mean value was 108.75 mg/kg) of cyanogens than the local varieties (mean value was 201.65 mg/kg). The concentrations of the cyanogen in all the cultivars investigated were far above the FAO/WHO recommended value (<10mg/kg). Hence, adequate detoxification and reduced frequency of consumption of these cassava cultivars are necessary in order to limit the ingestion of toxic levels of cyanide.