Controlling the properties of 3D-printed sodium caseinate emulsion gels by tuning starch-induced network architecture

This study explored the impact of varying cassava starch (CS) levels on the rheological and textural attributes and printability of sodium caseinate-cassava starch (NaCas-CS) composite emulsion gels. Increasing the CS content led to higher apparent viscosity and gel hardness, reduced fluidity, and promoted the formation of a tighter network. The composite containing 12% CS exhibited the best printing performance and dimensional accuracy, suggesting that an optimal balance of viscosity, hardness, and flow behavior is essential for successful 3D printing. Furthermore, increasing CS caused a leftward shift in relaxation time, indicating restricted water mobility and enhanced water-binding capacity. Microstructural analysis confirmed that elevated CS contents facilitated the development of a denser network. FT-IR analysis supported that the enhanced emulsion gel properties were driven by strengthened intermolecular interactions between CS and NaCas, including hydrogen bonding and electrostatic forces. These findings guide starch-enhanced 3D printability of protein gels and support starch-protein composites in food applications.