Intermolecular interactions influence the gelation and texture improvement of sodium alginate gels by edible dock protein

Increasing the mechanical strength of sodium alginate (SA) hydrogels is fundamental for extending their applications. In this study, the mechanical properties and gelation behavior of sodium alginate (SA) hydrogels were enhanced by incorporating varying concentrations of edible dock protein (EDP). The interactions between EDP and SA were systematically investigated. Our results indicated that the rheological and textural properties of the composite EDP-SA hydrogels were enhanced. When the EDP addition was 0.5g/100 mL, the porosity decreased by 6.9%, the hardness and storage modulus (G') increased by 22.3% and 32.1%, respectively, compared with those of the SA monohydrogel. Hydrogen bonding and hydrophobic interactions increase the α-helix and β- sheet contents, resulting in the stability of the network structure and the ordering of proteins. This study offers both theoretical and technical insights for developing high-performance SA-based composite hydrogels, broadening their potential applications in the food, biomedical, and biomaterial industries. • 0.5% EDP enhances SA hydrogel hardness by 22.28% and G' by 31.69%. • EDP-SA gel has a reduced cavity gap and a dense network structure. • Hydrogen bonds and hydrophobic interactions drive EDP-SA folding and densification.