Abstract

Pasting properties of starches and physico functional properties of proteins from some underutilized legumes

Author(s): I.W.Ofosu1, I.Oduro, G.M.Ankar-Brewoo, B.N.Opoku, M.B.Peterson

Neglected and underutilized legumes abound in storage proteins and starches but are not exploited to the fullest for industrial applications. Thus this study was to investigate the surface functional properties of the storage proteins and the pasting properties of their starches. The pasting properties of the starches were studied using Brabender viscoamylograph. Four factors; concentration of protein (0.01-0.08%), pH (7-10), source of protein (V. subterranea, C. ensiformis and C. cajan) and type of solvent for extraction (0.01M NaOH, 0.05M NaCl) were projected into quadratic model to study the two main surface responses of the isolated proteins; foaming properties and emulsion capacities. The V. subterranea starch hadmaximum paste viscosity (400 BU) and a breakdown viscosity of 21 BU compared C. ensiformis starch. The optimum surface functional properties was respectively achieved at protein concentration, pH, solvent and protein source of 0.08%, 8.5, NaOH and V. subterranea. The surface functional properties of foaming and emulsion capacities could be attributed to the storage protein of 80kDa present at 70%in the V. subterranea NaOH extract. The potential therefore exist for food industrial applications of V. subterranea as far as pasting and surface functional properties are concerned.