Characterization, release and antioxidant activity of curcumin-loaded amaranth-pullulan electrospun fibers

•We developed electrospun fibers from API:Pul to encapsulate and protect curcumin.•We studied physicochemical properties of curcumin-loaded electrospun fibers.•Antioxidant activity of curcumin was maintained after an in vitro digestion process.•Protein ratios used to make electrospun fibers determine the release of the bioactive.•GRAS characteristics of the matrix used allow its application in edible films.

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 ∼73% and ∼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.