Composition and nutritive value of cormels of Colocasia esculenta (L.) Schott

The nutritional quality of the cormels of Colocasia esculenta (L.) Schott cultivar ‘Guavir’ was determined chemically and biologically in feeding experiments with weanling rats. The contents of starch and unavailable carbohydrates (cellulose, hemicellulose and pectin) were 54 and 15% of the dry matter respectively. Lipid accounted for less than 1% of the dry matter. Palmitic, oleic and linoleic acids were the main fatty acids in the lipids, with linoleic acid predominating. The content and fatty acid composition of the individual lipids was examined. Crude protein amounted to 10.4% of the dry matter. This protein was low in the sulphurcontaining amino acids and tryptophan, but contained adequate levels of the other essential amino acids. Diets containing raw cormel meal gave severely depressed net protein utilisation (NPU) and total nitrogen and carbohydrate digestibility when fed ad libitum to weanling rats. Both NPU and nitrogen and carbohydrate digestibility improved when the cormel meal was cooked prior to inclusion in the diets but such diets still did not support growth in weanling rats.