Nutritional and antioxidant potential of a desert underutilized legume - tepary bean (Phaseolus acutifolius). Optimization of germination bioprocess

Tepary bean (Phaseolus acutifolius) is a short life cycle legume, resistant to many diseases and drought, originally from the deserts and semi-arid environment of Northwestern Mexico and the Southwestern US. Its mature seeds are scarce consumed, and their high protein and carbohydrate contents are underutilized. The aim was to identify optimal germination conditions for producing a functional flour with maximum values of protein content (PC), antioxidant activity (AoxA), and total phenolic content (TPC). A central composite rotatable experimental design with two factors [Germination temperature (GT, 20-40 degrees C)/Germination time (Gt, 10-170 h)] in five levels was used (13 treatments). Optimized conditions of germination to obtain a functional tepary bean flour were GT=32 degrees C/Gt=120 h. Germination was an effective strategy to increase PC (+57.5%), AoxA (+188-318%), TPC (+232%), flavonoid content (+114), and dietary fiber (+246%) in tepary bean seeds. Therefore, the optimized germinated tepary bean flour could be used as a source of natural antioxidants, protein, and dietary fiber in the formulation of functional foods.