Characterization of a novel chickpea protein-pullulan hydrogels that efficiently load and release sodium salts: Microstructures, molecular dynamics, and rheological properties

This study investigated the gel properties, structural characteristics, and Na + loading capacity of hydrogels formed by chickpea protein isolate (CPI) and pullulan (PUL). The aim was to explore their potential as polymers for enhancing Na + distribution and facilitating Na + release in reduced-salt foods. The results showed that the CPI-PUL hydrogels added with 2 % PUL exhibited the highest water holding capacity (70.78 %) and gel strength (493.06 g·mm). Molecular docking analysis indicated that the interactions between CPI and PUL primarily involved hydrogen bonding, hydrophobic interactions, and van der Waals forces. The incorporation of PUL resulted in a denser and more stable network of the hydrogels, which enhanced their thermal stability and mechanical properties. Results from cold-field scanning electron microscopy demonstrated that the hydrogel network structure remained stable at a PUL content of 2 %. Furthermore, fluorescence inversion microscopy and energy dispersive spectroscopy confirmed that the CPI-PUL hydrogels were stably loaded with sodium salts.