Composition of Two Local Cassava Varieties and the Effect of Processing on their Hydrocyanic Acid Content and Nutrient Digestibility by the Rat

Abstract

Two common Nigerian cassava varieties Were subjected to proximate analysis with a view to assessing the relative potential nutrient composition of the roots, stems, leaves and seeds. The results obtained showed that the leaves, seeds and stems in that order are much richer than the roots in protein but higher in crude fibre. There was a relationship between the crude protein contents of the roots and stem and the hydrocyanic acid (HCN) content of the plant while that of the leaves and seeds did not appear to follow the same trend. HCN of the bitter cassava variety was considerably higher in the whole tuber, pulp and peel than in the sweet strain, sundrying and ensiling resulted in appreciable losses of HCN. Grated root lost about half its HCN content within six hours while stored whole roots showed a rapid decline in HCN from the fifth day after harvest. Apparent digestibility coefficients (A.D.C.) of the major nutrients of cassava roots were not significantly (P <0.05) affected by the processes of boiling or sundrying.