Effect of cooking methods on proximate composition, gross energy and dietary fibre of some green leafy vegetables

N.O.A. ILELABOYE, I.A. AMOO2,

Abstract

The human population in tropical Africa denpends largely upon a large number of edible leaves to meet up with shortage in essential nutrients such as protein, mineral, and vitamins. Seven tropical vegetable species (Talium triangulae, Amaranthus hybridus, colocaisa esculenta, Telfairia occidentails, Solanum nigrum, Carssocephalum crepidiodes, and cindosculus aconitifolis) that are used as soup condiments in Nigeria either in the processed or unprocessed forms, were subjected to tow cooking methods (cooking without blanching and cooking after blanching). The effect of these cooking methods on the proximate composition and dietary fibre of these vegetable species were subsequently determined. The result of the study revealed that blanching and cooking caused significant (p<0.05) reduction in the proteins, carbohydrate and gross energy values of the vegetables, while it led to significant (p<0.05) increase in moisture, fat, and crude fibre contents of the vegetables. Cooking has a resultant increase on the ash content of the vegetables. Generally cooking caused significant (p<0.05) reduction in dietary fibre and cell wall carbohydrate but a corresponding increase occurred in the soluble fibre content of the leafy vegetables.