Tripolyphosphate-chitosan-pea protein interactions confers long-term stability to 3D printed high internal phase Pickering emulsions

This research explores the interactions of tripolyphosphate-chitosan-pea protein (TPP-CS-PP) in improving the stability and storage of 3D printing food inks. Chitosan (CS) and pea protein (PP) were complexed at various concentrations with 80 % palm olein to produce high internal phase Pickering emulsions (HIPPEs) 3D printing food inks. The resulting CSPP HIPPEs exhibited shear-thinning behaviour and the flexibility to switch between solid and liquid states, ideal for 3D printing. CSPP1:150 achieved the best 3D printing resolution and shape fidelity due to electrostatic attraction of CS-PP and excess PP enhancing adhesion at the oil/water interface. After spraying tripolyphosphate (TPP), crosslinking with CS and phosphorylation of PP further improved HIPPE resistance to deformation and oiling off for 2 days post-printing. This is a significant improvement over the control. Thus, further investigation on the interaction of TPP with CS and PP is warranted to further improve the storage stability of 3D printed food inks.