Evaluation of 3D Printing Performance and Multi-Response Optimization of Process Parameters of Brown Rice Flour Gel: From Rheology to Printed Structure

To enhance the molding accuracy and printability of brown rice flour gel (BRFG) in 3D food printing, this study systematically investigated the rheological properties of BRFG at various concentrations (20%, 24%, 28%, 32%, and 36%) and evaluated its printing performance under different process parameters (layer height, nozzle height, nozzle diameter, and printing speed). Rheological tests revealed that a moderate consistency coefficient ( K ), power-law index ( n ), and high energy storage modulus ( G ′) synergistically enhanced the printability of BRFG, with the optimal concentration identified as 28%. The printing speed and nozzle diameter significantly impacted dimensional accuracy of BRFG in the X-Y plane, while dimensional deviation in the Z-direction was influenced by layer height and nozzle height. Furthermore, the nozzle diameter served as the primary factor influencing hardness, whereas cohesiveness exhibited no statistically significant dependence on the process parameters. The BRFG printed at the optimal process parameters (a layer height of 1.2 mm, a printing speed of 16 mm/s, a nozzle height of 1.4 mm, and a nozzle diameter of 1.4 mm) exhibited superior dimensional fidelity and texture attributes. This study provides a theoretical foundation for the 3D printing application of BRFG-based foods. • The molding accuracy and 3D printability of brown rice flour gel (BRFG) are enhanced. • Printing speed and nozzle diameter determine the printing accuracy of BRFG in the X-Y plane. • Printing accuracy of BRFG in the Z-direction depends on layer height and nozzle height. • Hardness of BRFG is influenced by nozzle diameter among four process parameters. • Cohesiveness of BRFG shows no statistically significant dependence on the process parameters.