Applicability of Rice Doughs as Promising Food Materials in Extrusion-Based 3D Printing

3D food printing has attracted considerable attention as promising technique to manufacture foods customization in shape, color, texture and even nutrition. In this study, the effect of material formulation (water content and rice types including waxy rice, japonica rice, and indica rice) on the quality of 3D-printed rice-based foods was investigated. Results showed that rheological properties of rice doughs were obviously influenced by its formulation and qualitatively but not quantitatively correlated with its printability ever further. The 3D-printed waxy rice product with flour-to-water ratio of 100:90 (3DWRD-3) exhibited best shape, highest precision, and most compact microstructure, followed by indica rice product (3DIRD-2) and japonica rice product (3DJRD-4) with flour-to-water ratio of 100:85 and 100:95, respectively. To further study the compatibility of 3D printing with conventional food processing technologies, 3D-printed products were steamed. The study revealed that 3DWRD-3 has swollen during steaming due to the highest amylopectin content of waxy rice and further showed the worst shape stability and highest in vitro starch digestibility. But opposite phenomenon arose in steamed 3DIRD-2 and steamed 3DJRD-4, indicating that indica and japonica rice could be promising materials for 3D printing.