Phytochemical, nutritive and anti-nutritive composition of cassava (Manihot esculenta L) tubers and leaves
AbstractThe phytochemical, nutritive and antinutritive composition of Cassava (Manihot esculenta L) tubers and leaves were investigated. The presence of alkaloids, flavonoids, tannins, cardiac glycosides, anthraquinone, phlobatinnins, saponins and anthrocyanosides in aqueous and ethanolic extracts of raw tubers and leaves were determined. The proximate moisture, fat, fibre, protein, ash, and carbohydrate in the raw and boiled cassava tubers and leaves were determined. Vitamins A, C and E antinutrients such tannins, oxalate, phytate, trypsin inhibitor activity and some minerals were determined.
The aqueous and ethanolic extracts of raw cassava tuber contain alkaloids, flavonoids, tannins, reducing sugars and anthocyanosides, but do not contain cardiac glycosides, anthraquinone, phlobatinnins and saponins. The raw cassava leaves had more presence of alkaloids, flavonoids, tannins, anthraquinone, phlobatinnins, saponins, reducing sugars and anthrocyanosides., but do not contain cardiac glycosides. The proximate composition of the raw and boiled cassava tubers were not significantly different (p>0.01), except in the carbohydrate, fat and moisture. Raw cassava leaves contain more crude fibre and protein as compared to the raw or boiled cassava tubers. Vitamins A, C and E and minerals, namely, calcium, magnesium, phosphorus, iron, sodium, and chloride ions were identified in the raw and boiled cassava tubers and raw leaves and their levels were significantly reduced by boiling. Raw cassava leaves contain more antinutrients, such as tannins, oxalate, phytate and higher trypsin inhibitor activity than in the raw tuber.
Data of the study indicate that raw and boiled Cassava tubers and leaves may possess some medicinal properties, since they contain several active ingredients. Raw and boiled Cassava tubers are good sources of water and carbohydrate, while the raw leaves are rich in crude fibre, protein and water. The proximate composition of cassava tubers were essentially unaffected by boiling. The high contents of the antinutrients in the raw cassava leaves and tubers make them unsafe and unsuitable for human consumption, expect after processing. Cassava tubers and leaves contain vitamin A, C and E and several minerals, which are useful for the maintenance and growth of body tissues.
Keywords: phytochemistry, nutritive, antinutritve, composition, cassava tubers, leaves
Nigerian Food Journal Vol. 23 2005: 40-46
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