Nutritional Evaluation of Bean (Phaseolus Vulgaris) Protein. In Vivo Versus in Vitro Procedure

Digestibility (D), Biological Value (BV) and Net Protein Utilization (NPU) of whole bean flour and of the protein fractions glutelin (GLU), globulin (GLO), globulin GI (GI), albumin (ALB) and a protease inhibitor/lectin rich fraction (PIL) were determined, after autoclaving (121C, 15 min). For the whole bean flour both in vivo and in vitro procedures were used. For the in vivo assay a nitrogen balance with rats was performed. In vitro evaluation was based on the mean essential amino acid index (MEAAI) and in vitro protein digestibility. Results for the whole bean flour (BF) showed no statistical differences (p ≤ 0.01) between in vivo and in vitro techniques. In vitro digestibility ranged from 75–93% for the protein fractions and was 76% for the whole bean protein; biological value for the protein fractions ranged from 62–79%, and was 85% in the whole bean protein; calculated NPU ranged from 47–76% for the fractions, and was 65% for the whole bean protein.