Understanding the structure and rheological properties of potato starch induced by hot-extrusion 3D printing

This work investigates the 3D printability of potato starch (PS). For this purpose, the structure and rheological properties of the PS-based ink under hot-extrusion 3D printing (HE-3DP) at different PS concentrations and printing temperatures were studied. PS concentration was found to determine the structure and rheological properties of the PS gel. The printing temperature was shown to influence the structural transformation of PS and closely linked to the rheological properties of the gel. PS samples of 15–25% concentration at 70 °C presented optimal printability, which showed the absence of the original granule, crystalline and lamellar structures, with the formation of a uniform and compact gel network. In this case, the rheological properties were in a suitable range for HE-3DP including G′ (615.72–1057.63 Pa), τy (89.389–263.25 Pa) and τf (490.00–1104.97 Pa), which provided the PS-based ink with smooth extrusion, excellent printing accuracy and high structural strength, suitable for applications such as food and biomedical materials.