Matrix transformation in fiber-added extruded products: Impact of different hydration regimens on texture, microstructure and digestibility

► Different hydration regimes studied for processing of extrudates with apple pomace. ► Water added (17% net moisture) in either preconditioner, extruder or half in each. ► Greater opportunity for hydration increased starch gelatinization and digestibility. ► Shorter hydration period resulted in uneven microstructure. ► Pomace reduced digestibility due to less gelatinization, compact product structure.