Design of structurally enhanced dual-network high internal phase emulsion gels for 3D-printable plant-based fat...

Developing 3D-printable high internal phase emulsion gels requires balancing semi-fluidity with mechanical strength. This study designed a gel system stabilized by complexes of carboxymethyl cellulose sodium and heat-induced soy protein isolate, achieving high oil content, structural integrity, and printability. The complexes reduced interfacial tension from 31.01 to 28.42 mN/m, decreased droplet size from 5.30 ± 0.62 to 3.84 ± 0.20 μm, and increased viscosity, enhancing emulsion stability. Addition of k-carrageenan improved yield stress and viscoelasticity, supporting shape retention during printing. Dual crosslinking transformed the microstructure into a dense, interconnected network, confirmed by cryo-SEM. The gels exhibited enhanced mechanical properties (compression modulus: 28.64 ± 2.84 kPa) and improved freeze-thaw stability (shrinkage: 4.5 ± 0.17 %). In vitro digestion showed increased free fatty acid release, indicating structural stability and lipid bioaccessibility. This work provides a strategy for fabricating structurally reinforced, 3D-printable plant-based fat substitutes with potential applications in healthy food innovation.