Production of isolates from bean and lentil: Bioactive compounds, functional and nutritional characterization

• Isolates improved crude and digestible protein, gelation, foaming, water, and oil retention capacity. • Isolates decrease antioxidant capacity, polyphenols, and dietary fiber. • Legume flour retained antioxidant activity and polyphenols, since these compounds are concentrated in the outer layers. • Raw seed isolates exhibited better functional properties, required fewer reagents, and reduced processing time. • The acid-base precipitation method was used to obtain isolates with 90% digestible protein The success of plant-based foods relies on selecting protein sources with optimal techno-functional and nutritional properties. Therefore, this study aims to obtain and characterize protein isolates from cooked and raw beans and lentils, focusing on their nutritional profile, techno-functional properties, and bioactive compounds. The optimized procedure involves alkaline extraction at pH 12 for cooked beans and lentils, at pH 11 for raw lentils, and at pH 9 for raw beans, followed by centrifugation. The protein pellet was precipitated at pH 4 for cooked bean and lentil, and at pH 3 for raw lentil, and similarly for raw bean. The isolates were dried in a spray dryer. The results showed that raw isolates improved the crude and digestible protein, gelation, foaming, and oil retention capacity compared to the corresponding cooked isolates and flour. The lentil and bean isolates, both cooked and raw, decreased in antioxidant capacity by 24%-70%. Dietary fiber decreased in both cooked and raw isolates. This study demonstrates that the isolation process using raw seeds requires fewer reagents, reduces processing time, and yields isolates with improved functional properties (WHC, OHC, foaming) and flavonoid levels compared to isolates derived from cooked seeds.