Gelatin/peach gum composite-stabilized high internal phase emulsion gels for 3D printing and fucoxanthin delivery

This study developed a high internal phase emulsion (HIPE) gel stabilized by gelatin/peach gum (GL/PG) composite microgels for fucoxanthin (FX) delivery. GL/PG composites (4:1-1:4) were characterized for wettability, interfacial activity, and molecular interactions. FX-loaded HIPEs (0.5-4% w/v particles) were assessed for droplet size, microstructure, rheology, print fidelity, stability, and digestibility. The GL/PG_3:1 composite showed balanced amphiphilicity (contact angle: ∼94.40°, interfacial tension: ∼24.05 mN/m). As the particle concentration increased from 0.5% to 3%, the HIPEs mean droplet size decreased significantly (p < 0.05) from 11.79 ± 0.21 μm to 2.65 ± 0.13 μm. Confocal microscopy revealed that the 3% formulation formed a dense and uniform interfacial layer with well-distributed oil droplets, whereas lower concentrations showed incomplete coverage and droplet aggregation. All HIPEs exhibited solid-like behavior (G' > G″) and shear-thinning. The 3% formulation achieved 99.40 ± 0.46% print fidelity, the lowest lipid hydroperoxides and malondialdehyde levels during accelerated storage, and significantly enhanced FX bioaccessibility (from 18.69% to 66.88%). These findings demonstrate that 3% GL/PG_3:1 composite microgels offer a viable strategy for producing 3D-printable HIPEs with improved stability, printability, and FX delivery efficiency, while also providing a new avenue for the high-value utilization of PG.