In this work, ultrathin electrospun fibers from two different blends of amaranth protein isolate (API) and the carbohydrate polymer pullulan (Pul) were loaded with two different concentrations of curcumin (0.05% y 0.075%). The loaded electrospun fibers were physicochemically characterized and the curcumin release profile as well as its antioxidant capacity under in vitro digestion conditions was evaluated. Round, uniform and homogenous fibers with diameters of around 224.5-248.6 nm were obtained for loaded API:Pul 50:50 fibers. The encapsulation efficiencies of curcumin varied between similar to 73% and similar to 93% for both loadings and fiber compositions. Moreover, a controlled and sustained released of curcumin was observed both in buffer solution (pH = 7.4) and during an in-vitro digestion process. The antioxidant activity of curcumin entrapped within the ultrathin fibers was maintained after the in vitro digestion process and it was superior in comparison with the non-encapsulated bioactive compound. (C) 2015 Elsevier Ltd. All rights reserved.