Impact of rheological properties of mashed potatoes on 3D printing

Rheological properties of the mashed potatoes (MP) with addition of potato starch (PS) and their 3D printing behavior were investigated. Both flow ramp and dynamic oscillation frequency experiments were used to characterize the rheological properties of the mixtures. The correlation between the formulation and processability during 3D printing was established. MP with 0% PS possessed low yield stress (tau(0)) (195.90 Pa) and printed objects deformed in sagged afterwards. Whereas, addition of 2% PS displayed excellent extrudability and printability, i.e., shear-thinning behavior, consistency index (K) of 118.44 (Pa.S-n), tau(0) of 312.16 Pa and proper elastic modulus (G'). At such condition, the printed objects possessed smooth shape, good resolution, and could withstand the shape over time. Although MP with addition of 4% PS represented good shape retention due to proper tau(0) (370.33 Pa) and G', the poor extrudability made it difficult to print due to high K (214.27 Pa.S-n) and viscosity. (C) 2017 Elsevier Ltd. All rights reserved.