Chemical and functional characterization of chickpea protein derivates

Abstract

Whole flour, defatted flour and freeze dried protein concentrate were obtained from chickpea. Protein solubility, water and oil absorption capacity, emulsifying capacity and emulsion stability, foaming capacity and foam stability were used to evaluate the chickpea protein derivates from a chemical and functional standpoint. The chickpea protein concentrate, obtained by alkaline solubilization (pH 10.5) followed by isoelectric precipitation at pH= 4.5 and freeze drying, displayed the highest protein content and the best functional properties. The profiles of the solubility curves corresponding to the chickpea protein concentrate indicate a minimum solubility at pH ranging from 4 to 5 (i.e., protein solubility of 12.5% in the case of chickpea protein concentrate) and two domains of maximum solubility at pH 1.8 and 11.8 (i.e., protein solubility of 53.2% and 85.7%, respectively, in the case of chickpea protein concentrate). The profiles of protein solubility curves are similar with the profiles of the emulsifying capacity vs. pH curves. The foaming capacity increased with the increase of chickpea protein concentration. After 120 hours of storage the foam stability was higher than 90%. The experimental data show that the chickpea protein concentrate can be successfully used as food ingredient due to its chemical composition and functional properties.