Evaluation of Methods for Roots Processing on Removal of Anti-nutritional Factors of Selected Cultivars of Cassava (Manihot esculenta C.) Grown in Ethiopia

Abstract

Locally grown cassava cultivars were subjected to study the effect of boiling, sun-drying and fermentation processing methods on removal of anti-nutritional factors. The root product flours were analyzed for anti-nutritional factors using standard methods. The data generated were statistically analyzed using statistical package for social scientists (SPSS). Out of the three processing techniques, fermentation of grated cassava roots for 72 hours sufficiently reduced HCN content to safe level (<10 ppm, WHO) of human consumption. The unprocessed cassava root of Gamo cultivar (48.00 ppm) belonged to the category of sweet or non-toxic. Whereas, cultivars of Hayik (78.07 ppm), 28 (83.70 ppm), 44/72-NW (129.20 ppm) and Koree (159.00 ppm) were found to be moderately toxic. Cultivars of 192 (211.17 ppm) and 5538-19 (247.20 ppm) belonged to highly bitter (highly toxic) cultivar too. Reduction in phytate and tannin levels were highest for sun-dried followed by fermented and boiled flours. However, reduction in oxalate contents were highest for fermented followed by boiled and sun-dried flours. The study reveals that the effect of processing methods found to be significant (P<0.05) on removing anti-nutritional factors.