Applicability of defatted soybean flours to 3D food printer: Effect of milling methods on printability and quality of 3D-printed foods.

Several particle sizes of defatted soybean powders were prepared by using a hammer mill and a jet mill, and their suitability for three-dimensional (3D) food printers was investigated. The particle sizes of the powders depended on the milling method, with cumulative volumes of 50% ranging from 6.1 μm in the jet mill to 93.3 μm in the hammer mill. Rheological properties of the pastes prepared by adding water varied with particle size, and jet-milled powders exhibited lower storage modulus, loss modulus and complex viscosity. These differences in rheological properties affect the printing performance, and the fine powders obtained from jet mill tended to have higher 3D printability in appearance in the range of 70–74% paste water contents. The milling method was found to have a significant effect on texture, and fine powders by jet mill was able to produce 3D-printed foods with a smooth surface structure.