Texture engineering of aquatic protein-based products via 3D food printing

• 3D printing used for engineering textural propeties of protein-based products. • Adjusting infill density can effectively customize firmness of the printed objects. • Engineering printing pathways can produce anisotropic textures in macroscale. • A customizable texture profile in different parts of a single product was developed. The versatility of 3D printing in digital design and material deposition explored to adjust the internal architecture of a large portion of a protein-based food. The effect of infill density, printing pathways and their combination in customizing textural properties of model products made of proteins from fish side streams were systematically investigated. A direct correlation between the infill density and uniaxial firmness of the printed objects was found. Using different printing pathways across the Z-axis showed that parallel printing pattern can produce anisotropic textures in macroscale. This was due to a nonhomogeneous load of materials in parallel with the printing pathways, compared with its perpendicular direction in mesoscale, as revealed with microtomography imaging. Using cross printing pathway design was found as a way to achieve isotropic textures. Finally, using a combination of infill density and printing pathways across the X, Y axis and vertically in a non-parallel manner within a large portion of a product was proven as a new route to achieve a customizable texture profile in different parts of a single product. Altogether, our results demonstrated new possibilities for the development of protein-based products with customized heterogenous textures, closer to those in muscle, using the 3D printing technology.