Egg White Peptide and Curcumin Synergistically Enhance the Interfacial Structure of Polysaccharide-Based High Internal Phase Pickering Emulsions, Which in Turn Improve Their Bioaccessibility

High internal phase Pickering emulsions (HIPPEs) stabilized by food-grade solid particles exhibit excellent biocompatibility, structural stability, and potential for delivery of functional factors, making them suitable for developing personalized, nutritionally rich high-value products. In this study, polysaccharide-based HIPPEs were stabilized by the interaction of β-cyclodextrin (β-CD) and chitosan hydrochloride (CHC). The results demonstrated that when 0.4% CHC was added and the aqueous phase pH was 4.0, β-CD and CHC formed a densely cross-linked interpenetrating network, driven by electrostatic repulsion and spatial hindrance. This network stabilized the HIPPE droplets, resulting in uniform droplet sizes with the smallest size of approximately (26.35 ± 8.83) nm. The HIPPEs effectively co-loaded hydrophilic (egg white peptide CYST) and hydrophobic (curcumin, Cur) bioactives, which enhanced the bioavailability of CYST and Cur to 94.83% and 75.93%, respectively. Moreover, the presence of multiple hydroxyl groups and binding sites in CYST and Cur facilitated the assembly of molecules at the interface into a three-dimensional network membrane, thus improving the stability of the emulsion. This study provides a reference for constructing functional polysaccharide-based HIPPEs and expanding their application in the food, cosmetic and coating fields.