Dual network interpenetration emulsion gels based on alginate and coffee cherry-derived polysaccharides: preparation, characterization, and curcumin delivery

Functional ingredient bioaccessibility is limited by instability and low solubility, thus, edible macromolecules are used to enhance delivery. This study presents a safe, sustainable method to prepare dual-network emulsion gel (CSEG). The gel is formed via Ca 2+ -induced crosslinking of sodium alginate (SA) and coffee cherry-derived polysaccharide (CCP) to enhance bioavailability. CCP and SA form a stable bimolecular network through hydrogen bonds and calcium ion coordination, improving gel stability. The effects of CCP/SA ratios on CSEG properties and curcumin delivery are also investigated. At the optimal CCP: SA mass ratio of 3:2, the system shows superior crosslinking, forming a strong gel that resists gastric shear while maintaining viscoelasticity. The curcumin-loaded CSEG demonstrates excellent pH stability, preserving curcumin in gastric fluid even in highly acidic conditions. In vitro digestion studies reveal that CSEG boosts curcumin bioavailability from 29.62 % to 63.94 %. This work reveals emulsion gel structure-function links, guiding bioactive carrier design.