Abstract

The study focused on the preparation of protein isolates from leaves of Basella alba (amunututu) and Senecio biafrae (worowo) leaves with the view to determining their in-vitro digestibility and functional properties. Fresh leaves of the vegetables were processed to obtain protein isolates by combination of solubilization, precipitation, centrifugation and freeze drying. The proximate analysis of the leaf meal and functional properties (bulk density, foaming properties, emulsifying ability and capacity, water and oil absorption capacity and in-vitro digestibility) of the isolate obtained from the leaves were determined using standard method. The protein contents of the protein isolates of Basella alba and Senecio biafrae were 89.75 and 67.50%, respectively; Water absorption capacity ranged from 240-305% for Basella alba and 200-285% for Senecio biafrae while oil absorptions were 140 and 190%, respectively; the least foaming capacities for the two isolates (30 and 40%, respectively) were obtained at pH 4 with poor stability at all pH. The lowest Emulsifying Activity Index was observed at pH 4 having values of 19.35 and 71.25 m2/g, respectively and the % in-vitro protein digestibility values were high ( 86.34 and 82.86%) for Basella alba and Senecio biafrae, respectively. The study concludes that leaves of Basella alba are good sources of protein and the proteins are easily digested by gastro-intestinal enzymes. The good functional properties exhibited by the isolates are indications that they could be used as food ingredients.