Effect of xanthan gum on physicochemical properties and 3D printability of emulsion-filled starch gels

The effects of xanthan gum (XG) concentration (0, 0.32%, 0.64%, 0.96%, 1.28%) on the rheological properties, microstructure, and 3D printing characteristics of emulsion-filled starch gels containing curcumin (XG-EFGs) were investigated. The results showed that the interaction between starch and XG led to an increase in mechanical strength with increasing XG concentration. The gels exhibited weak strain overshoot in large amplitude oscillatory shear tests, and the Lissajous curve shifted from elastic dominance to viscous dominance in the transition from linear to nonlinear behavior. The nonlinear parameters also demonstrated that the addition of XG led to strain stiffening and shear thinning behavior. Combining the rheological properties and 3D printing results, it was concluded that the addition of XG effectively improved the dimensional accuracy and stability of the printed products. Also, the addition of XG decreased the hardness, springiness, and gumminess of the XG-EFGs, changed the color brightness,and resulted in a superior delivery system for curcumin. This research contributes to the development of 3D printed gel foods fortified with lipophilic nutrients.