Tea eggs-inspired Pickering emulsion stabilized by cooked egg white protein-EGCG complexes: Astaxanthin loading and 3D printing.

Astaxanthin (AXT) demonstrates significant potential in food applications due to its diverse biological activities. However, its practical implementation is constrained by poor water solubility, environmental instability, and low bioavailability. This study aimed to leverage Pickering emulsions stabilized by heat-denatured egg white protein (EWP)-EGCG complexes as carriers for AXT encapsulation, and exploring the system's feasibility in 3D food printing. The results revealed that EWP and EGCG formed complexes through electrostatic and hydrogen bonding interactions. The emulsions exhibited exceptional stability, favorable viscoelasticity and thixotropic recovery. <i>In vitro</i> digestion experiments showed that the 1% EWP-EGCG complex-stabilized emulsion released 29.61% AXT in gastric fluid and 81.03 % AXT in intestinal fluid, demonstrating pH-dependent controlled-release behavior. Additionally, the emulsion had higher scavenging rates of DPPH, ABTS and hydroxyl radicals, which were 96.05%, 95.05% and 59.02%, respectively. Notably, the system demonstrated excellent 3D printing accuracy and structural support, making it a promising food-grade edible ink.