Extrusion-based 3D printing of high internal phase emulsions stabilized by co-assembled β-cyclodextrin and chitosan

beta-cyclodextrin (beta-CD) modified by chitosan (CS) via electrostatic interactions and hydrogen bonds was used to fabricate high internal phase emulsions (HIPEs) for food 3D printing. The most promising ink for 3D printing was screened among HIPEs stabilized by polysaccharide complexes at CS concentrations of 0.08-0.40 wt% and pH values of 3-7. The beta-CD/CD complexes formed by 1.20 wt% beta-CD and 0.32 wt% CS at pH 5 possessed proper wettability and interfacial tension, forming an interfacial membrane, which could offer sufficient electrostatic repulsion and steric barrier against the coalescence of emulsion droplets. Rheological analysis indicated that HIPE stabilized by beta-CD/CS complexes at 0.32 wt% CS and pH 5 has good printing potential in three stages of 3D printing: extrusion (shear-thinning behavior), recovery (excellent thixotropy), and self-supporting (sufficient storage modulus and yield stress). Subsequently, 3D printing results of plane and stereo models also demonstrated that HIPE stabilized by these complexes possessed the best printability. This study obtained food-grade inks with outstanding extrudability, recoverability and self-supporting properties by a simple and easy method, providing ideas and guidance for applying polysaccharide-based HIPEs in 3D printing.

Automated summary

This study developed high internal phase emulsions (HIPEs) for food 3D printing by modifying beta-cyclodextrin (beta-CD) with chitosan (CS) and identified the most promising ink for 3D printing. The HIPE stabilized by beta-CD/CS complexes exhibited excellent rheological properties and showed the best printability in both plane and stereo models.