Enzymatic hydrolysis facilitates nanofibrils formation desired for iron nanoparticles stabilization

Iron nanoparticles (Fe NPs) offer a sustainable strategy to control iron deficiency anemia (IDA), while their tendency for oxidation severely limits their application. In this study, soy protein nanofibrils (FibSPH_Fla) fabricated via enzymatic hydrolysis could act as colloidal stabilizers for Fe NPs. Notably, enzymatic hydrolysis could remarkably reduce the fibrillization time from 24 h to 5 h where mature and curled nanofibrils were obtained without prolonged acid-heating. Accordingly, Fe NPs could uniformly decorate the surface of the fibrils by binding to the amide and carbonyl sites of the protein and maintained in Fe (II) state. The formed iron-protein nanofibrils (Fe FibSPH_Fla) exhibited enhanced stability against storage and gastrointestinal digestion. Compared to traditional iron fortifiers, Fe FibSPH_Fla showed reduced cytotoxicity with minimal organoleptic changes. Additionally, Fe FibSPH_Fla could effectively retard lipid oxidation of emulsions. These findings served soy protein nanofibrils as a promising delivery vehicle for iron fortification.