Lactoferrin-chitosan composite hydrogel: a dysphagia-oriented carrier for sustained ergothioneine delivery

Amid the rapid aging of the population, dysphagia prevalence is steadily increasing, largely driven by oxidative stress, which accelerates neuronal injury and indirectly compromises swallowing function. To address this challenge, we developed a food-grade lactoferrin-chitosan (LF-CS) composite hydrogel as a functional delivery system for ergothioneine (EGT). The incorporation of LF modulated the hydrogel's textural properties by reducing hardness and enhancing elasticity. This adjustment aligned the hydrogel with IDDSI Level-4 criteria, highlighting its potential for practical food applications. FTIR and XPS analyses demonstrated that genipin crosslinking enabled covalent network formation, while hydrogen bonding and electrostatic interactions among LF, CS, and EGT further stabilized the matrix, as evidenced by systematic shifts in CO and N 1 s binding energies. CH4 outperformed CS with the highest EGT encapsulation efficiency (78.33%), evidenced by significantly higher DPPH and ABTS scavenging rates. In vitro release studies showed that CH4 effectively suppressed premature gastric release while promoting sustained intestinal release, confirming its controlled-release potential. LF-NMR analysis further revealed that CH hydrogels optimized water distribution by increasing both bound and free water, while maintaining a porous structure favorable for stabilization and sustained release. Overall, this work provides a food science-oriented strategy for integrating texture modulation with controlled nutrient delivery, offering a promising platform for the development of dysphagia-friendly functional foods targeting oxidative stress and age-related swallowing disorders.