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 (FibSPHFla) 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 FibSPHFla) exhibited enhanced stability against storage and gastrointestinal digestion. Compared to traditional iron fortifiers, Fe FibSPHFla showed reduced cytotoxicity with minimal organoleptic changes. Additionally, Fe FibSPHFla could effectively retard lipid oxidation of emulsions. These findings served soy protein nanofibrils as a promising delivery vehicle for iron fortification.