Protein Quality and Antinutritional Factors of Wild Legume Seeds from the Sonoran Desert

Seeds from seven species of legume trees of the Sonoran Desert were studied to determine their potential value as a nonconventional food and/or as a feed source. Seed proximal composition and protein quality were evaluated by conventional methodology. Defatted flours from Acacia farnesiana, Cercidium microphyllium, Cercidium sonorae, Mimosa grahamii, Olneya tesota, Parkinsonia aculeata, and Prosopis juliflora have protein contents that ranged from 20 to 30%. These proteins were deficient in sulfur amino acids but high in lysine and phenylalanine content. Except for M. grahamii seeds, trypsin inhibitors were relatively high in all species and varied from 50 to 70 TIU/ g. Other antinutritional factors as lectins, alkaloids, saponins, and phenols were detected in all but Mimosa seeds. Protein in vitro digestibility was found to be 77-84%, and these values increased (5-10%) after a thermic treatment. The calculated C-PER values were found to be 1.8-2.1%. From the seeds of the seven species evaluated, M. grahamii showed the highest potential as a protein source.