Keywords: 4D printing; high internal phase emulsion; pea protein isolation; Sodium alginate
This study explored the feasibility of high internal phase emulsions (HIPE) stabilized by pea protein isolation-sodium alginate complexes (PPI-SA) as 3D/4D printing inks and curcumin delivery vehicles. Interfacial viscoelasticity was investigated using QCM-D, indicating that stronger electrostatic interactions between PPI and SA occurred under pH 3.0-5.0, generating more viscoelastic layer, contributing to steric stabilization of emulsions. Therefore, HIPE fabricated using PPI-SA at pH 3.0-5.0 (HIPE-C3-5), with PPI prepared at pH 6.0 (HIPE-P) as a control. Rheological results demonstrated that HIPE-C exhibited shear-thinning (extrudability), high G' and G'' (self-supporting) at low pH. Subsequently, HIPE-C 3D-printed the selected shapes with high resolution and fidelity at low pH. Simulated digestion results showed HIPE-C3 exhibited higher bioaccessibility of curcumin than HIPE-P. Moreover, curcumin-HIPE-C3 changed color in response to alterations in NaHCO3 concentrations. These findings provided theoretical reference for further applications of HIPE in 4D printing in food industry.
