Effect of Processing and Gum Arabic Addition on the Composition and In Vitro Functional Properties of Faba Bean (Vicia faba L.) Pod Flour

The valorization of agri-food by-products as functional ingredients requires understanding how processing and formulation affect their nutritional and metabolic properties. This study evaluated the combined effects of drying method (hot air drying, HAD; freeze-drying, FD), particle size (80 and 500 µm), and gum Arabic (GA) addition on the compositional and metabolic functionality of faba bean (Vicia faba L.) pod flour. Proximate composition, total phenolic content (TPC), estimated glycemic index (eGI), glucose dialysis retardation index (GDRI), and enzyme inhibitory activities (α-glucosidase and pancreatic lipase) were determined. Results showed that all factors significantly affected eGI, with independent contributions, whereas GDRI was mainly influenced by particle size and GA, with significant interaction effects. GA addition consistently reduced eGI and increased GDRI, indicating improved modulation of both starch hydrolysis and glucose diffusion. HAD samples showed higher enzyme inhibitory activity, while FD combined with GA enhanced TPC. Particle size modulated structural properties affecting starch accessibility and glucose diffusion. Soluble dietary fiber and phenolic compounds were key contributors to in vitro metabolic functionality, while matrix structure determined their effectiveness. These results suggest that faba bean pod powders may serve as sustainable functional ingredients for food applications, contributing to the valorization of agri-food by-products within a circular economy approach.