Effect of drying methods on physico-chemical and functional properties of chickpea protein concentrates

Abstract

Chickpea protein concentrates (CPCs) were prepared from seed flour by alkaline extraction followed by isoelectric precipitation. The effects of different drying methods (freeze drying and convective drying at 40°C and 50°C) on physico-chemical and functional properties of CPCs were investigated. CPCs were found to have high contents of protein (61.20–63.12% dry weight basis). Freeze dried concentrate had the highest values of water and oil holding capacities. This drying method gave the lightest CPCs color. The amino acid of CPCs could reach the FAO/WHO requirement (1990) for the essential amino acids for preschool children and the sulfur-containing amino acids were the first limiting amino acids for all three protein concentrates. The solubility-pH profile of different CPCs showed minimum solubility when the pH was between 4.0 and 5.0. All concentrates were able to decrease the interfacial tension. The thermal properties of CPCs were studied by differential scanning calorimetry. CPCs differed significantly (p⩽0.05) in peak denaturation temperature and enthalpy of transition. Hence, drying methods used for the preparation of CPCs powders can affect the physico-chemical and functional properties.