Investigation of carrot/squid blends as edible inks for extrusion 3D printing: Effect of hydrocolloids incorporation

Extrusion-based food printing is an emerging technology that enables the creation of personalized food products in terms of shapes and designs while satisfying individual nutritional and sensory requirements. The present study focused on the optimization of carrot- and squid-based ink formulations for extrusion-based three-dimensional (3D) printing while systematically investigating the impacts of varying hydrocolloids on the water retention, rheological characteristics, and printing performance of the inks. Of the ten food hydrocolloids, xanthan gum (XG) and alginate had the greatest effect on preventing water syneresis in the inks. Moreover, the inks supplemented with hydrocolloids exhibited proper shear-thinning behavior, softer network strength, and lower yield stress than the control ink. Three-interval thixotropy (3ITT) test results also revealed an enhanced solid-like character after nonlinear deformation in the inks with XG, alginate, or high-methoxyl (HM) pectin addition. Finally, 3D printing assessment showed that only the addition of XG or alginate allowed smooth extrusion and precise filament stacking into the predefined geometry, which was attributed to the homogeneity of the inks resulting from their superior water-holding capacity. 3D constructs fabricated using XG-added ink achieved time-dependent structural stability, whereas alginate addition caused slight filament sagging owing to insufficient self-supporting ability. Collectively, XG was found to be the best additive for carrot/squid-based printing, providing useful suggestions for future investigations on determining the 3D/4D printing and post-printing processes of carrot or squid powder-based nutritious inks.