3D printing food ink development using Auxenochlorella protothecoides: Rheology, printability, and fish texture simulations

This study explores the potential of microalga ( Auxenochlorella protothecoides ) as seafood ink for a three-dimensional (3D)-printed product that replicates fish texture. Food inks were prepared with varying concentrations of microalga and their suitability for 3D-printing was evaluated through a rheological analysis. The concentration showing the highest printability was then selected to assess the effects of 3D-printing parameters on the texture of printed samples. Initially, the food ink was suitable for 3D printing across all microalga concentrations due to its shear-thinning behavior, but increasing microalga content lowered the flow index and reduced printability. Optimal printability was achieved at a microalga concentration of 36%, where both height and width percentage errors were 0%, closely matching the computer-aided design. Using this ink, the physical properties of the 3D-printed models were examined based on printing parameters. Various physical properties depended on the nozzle diameter and infill density, with the resulting textures closely matching those salmon, mackerel, and flounder. These findings suggest that microalga can be used as food ink in 3D printing of fish substitutes that replicate the texture of real fish. • Auxenochlorella protothecoides inks enable sustainable, customizable fish analogs • A printability window was defined using rheology, microstructure, and printing data • Thixotropic recovery and fidelity metrics identified the optimal ink formulation • Nozzle diameter and infill density tune printed hardness to mimic fish texture