One-Step Fabrication of Dual-Network Corn Starch–Sodium Alginate Emulsion Gels to Improve Curcumin Stability and Bioaccessibility

This study established a one-step method to fabricate corn starch-sodium alginate (CS–SA) dual-network emulsion gels, in which the key structural framework was constructed via hydrogen bonding between starch molecules coupled with Ca²⁺-mediated ionic cross-linking of SA. We systematically examined the influence of varying SA concentrations on mechanical properties, rheological behavior, microstructure, encapsulation efficiency, environmental stability, and simulated digestion properties of CS-SA dual-network emulsion gels. At 2% SA concentration, the emulsion gel exhibited optimal performance, demonstrating superior gel strength (382.89 ± 71.89 g) and water-holding capacity (99.90%) compared to the control (CS-SA 0% ). The CS-SA 2% emulsion gel formulation also showed enhanced photothermal stability and achieved an exceptional encapsulation efficiency of 95.68%. In vitro digestibility studies revealed that the CS-SA 2% emulsion gel provided the highest curcumin bioaccessibility (37.22%). These findings establish a theoretical foundation and practical methodology for utilizing natural starch-based dual-network emulsion gels in delivery systems.