Techno-Functional, Antioxidant, and Sorption Properties of Dietary Fiber Concentrates from Guamuchil (Pithecellobium...

Guamuchil (Pithecellobium dulce) is an underutilized legume with significant potential as a food ingredient. This study valorized guamuchil fractions (pulp, peel, and seed) by developing dietary fiber concentrates (DFC) and evaluating their physicochemical, techno-functional, and antioxidant properties using a single-factor completely randomized design. Proximate composition and dietary fiber profiles (2011.25) were analyzed following AOAC official methodologies. Results showed the peel fraction contained the highest total dietary fiber (64.16 ± 1.23 g 100 g^-1 dry basis (db)) and total phenolic content (15.46 ± 0.26 mg GAE g^-1 db), positioning it as a bioactive fiber source. Conversely, the pulp DFC exhibited superior hydration properties, with high solubility (43.54 ± 1.22%), swelling (10.23 ± 0.30 mL g^-1 db), and water retention capacity (14.17 ± 0.35 mL g^-1 db), making it suitable as a texturizer. Moisture sorption isotherms exhibited type II sigmoidal behavior, accurately fitted by GAB and Peleg models (R² ≥ 0.997). The pulp showed higher hygroscopicity and water binding ability, whereas peel and seed fractions displayed lower sorption and enhanced stability. These findings demonstrate that Guamuchil DFCs are suitable as a potential food formulation ingredient owing to their high functionality.