Effect of cooking methods on mineral and anti nutrient composition of some green leafy vegetables

Abstract

The human population in tropical Africa depends largely upon a large number of edible leaves to meet up with shortages in minerals and vitamins. Seven tropical leafy vegetable species (Talium triangulae, Amaranthus hydrides, Colocaisa esculenta, Telfairia occidentials, Solanum nigrum, Crassocephalum crepidiodes, and cindosculus aconitifolis) that are used as soup condiments in Nigeria either in the processed or unprocessed forms, were subjected to two cooking methods (cooking without blanching and cooking after blanching). Herein, we report the effect of these cooking methods on the mineral contents and anti nutritional components of the seven tropical leafy vegetables. There is varietal influence on the mineral and anti nutritional contents of the vegetables. All the mineral elements; Calcium, Phosphorus, Potassium, Magnesium, Iron, Manganese, Copper and Zinc, except Sodium (155.14mg/Kg to 4759.80mg/Kg) were reduced by the cooking methods. There was 45.96% to 69.33%, 39.22% to 64.42%, 76.71% to 87.88%, 68.10% to 98.33% and 78.78% to 88.02% reduction in phytate, oxalate, saponin, tannin and cyanide contents of the vegetables respectively due to cooking methods.