Lupinus angustifolius protein isolates: chemical composition, functional properties and protein characterization

Two types of protein isolates were prepared from Lupinus angustifolius defatted flour by alkaline extraction, with (Isolate B) and without (Isolate A) sodium sulphite, and acid precipitation of proteins at the isoelectric point (IEP 4.3). Chemical composition, main functional properties and protein composition of L. angustifolius defatted flour and protein isolates were determined. Isolate A and B have 93.9 and 84.6% protein content, respectively, and had a balanced composition of essential amino acids, with respect to the FAO pattern except for lysine. The in vitro protein digestibility ranged between 86.3 and 93.9% for isolate A and B, respectively.