Lactoferrin thermal stabilization and iron(II) fortification through ternary complex fabrication with succinylated...

A thermally stable co-delivery system for lactoferrin (LF) and iron(II) was developed to address iron deficiency anemia. Complexes were formed between LF, succinylated sodium caseinate (S.NaCas) and FeSO₄ with high yield (∼85%). LF-S.NaCas-Fe complexes achieved loading capacities for iron(II) between 2.5 and 12 mg g^-1and LF loading capacities between 250 and 690 mg g^-1, depending upon initial Fe²⁺ concentrations and LF ratios. The LF-S.NaCas complex mixtures appeared as smooth cubic particles in SEM, and gradually aggregated to amorphous particles as th iron(II) concentration increased due to iron-facilitated cross-linking. The complexation significantly improved LF thermal stability and addressed the poor solubility of iron(II) under neutral pH. After thermal treatment (95 °C, 5 min), the rehydrated complexes retained 68%-90% LF, with <10% iron(II) release. Circular dichroism spectra showed the secondary structure of the complexed LF was well retained during thermal treatment. This thermally stable system showed great potential in LF thermal protection and iron(II) fortification.