Effect of genotype on the physicochemical and functional attributes of faba bean (Vicia faba L.) protein isolates.

The functionality and surface characteristics of protein isolates prepared from seven genotypes of faba bean were investigated. All factors studied were independent of genotype. The average protein and isolate (~94% protein) yields were ~77% and ~25%, respectively, using an alkaline extraction process followed by isoelectric precipitation. The overall averages were: surface charge +22.1 mV, surface hydrophobicity 47.2 arbitrary units, and surface and interfacial tensions of 65.0 mN/m and 10.7 mN/m, respectively. The ratio of the major globulin fractions (legumin:vicilin) shifted from 3.8 for the flours to 4.5 in the isolates. Average values for foaming capacity and stability, emulsion capacity, creaming stability, oil holding capacity, emulsifying activity and stability indices, and solubility were 162.0%, 65.0%, 184.0 g/g, 94.0%, 5.7 g/g, 13.0 m2/g, 10.7 min, and 81.0%, respectively. The lack of significant varietal effects would be advantageous to food processors as the source of the feedstock would not affect ingredient functionality.