Effect of three processing methods on some nutrient and anti-nutritional factor constituent of Colocasia esculenta (Amadumbe)

Abstract

Colocasia esculenta L. Schott (Amadumbe) is a major starchy food crop used in the rural areas in Kwazulu-Natal province, South Africa. Like most root crops, Amadumbe is rich in carbohydrate content with low protein and lipids. Preliminary screening of Amadumbe revealed the presence of some anti- nutrients (amylase inhibitor, trypsin inhibitor, oxalate, alkaloids, saponin, phytate and total phenols). The effect of various domestic processing (boiling, roasting and frying) on the levels of the anti-nutrients in Amadumbe tubers was investigated. A ‘white’ and ‘purple’ (local denomination) Amadumbe variety was used. Anti-nutrients were reduced (6-90%) by the domestic processing techniques. Of the three different treatments, boiling appeared to be the most effective in reducing levels of all the investigated anti- nutrients in both Amadumbe varieties. It is therefore concluded from the results of this study that the anti-nutritional factors, though present in raw tubers, should not pose a problem with regard to human consumption if the tubers are properly processed.