Advancing sustainable food layered manufacturing through 3D printing and post-processing of butterfly pea flower

Purpose This study aims to develop a printable, plant-based food ink using butterfly pea flower (BPF) blended with cookie flour and to optimize extrusion-based 3D printing parameters to achieve consistent print quality, structural integrity and nutritional retention in food layered manufacturing (FLM). Design/methodology/approach The research assessed the extrusion printability of the BPF-based food ink by evaluating its rheological properties. Proximate composition, color and texture analyses were performed to characterize the ink, while sensory evaluation was conducted to assess consumer acceptability. Printing parameters, including nozzle diameter, motor speed, nozzle height and print speed, were systematically optimized to achieve consistent extrusion and structural fidelity. Experiments were conducted in triplicate (n = 3), and results were evaluated using statistical tests (ANOVA, p < 0.05). Following the FLM process, post-processing treatments, such as steaming, frying and microwave drying, were applied to assess their effects on the printed constructs. Findings The BPF food ink exhibited favorable shear-thinning behavior, effectively modeled by the Herschel−Bulkley equation, and demonstrated consistent extrusion with high-resolution printability. The optimal printing parameters were established as a nozzle diameter of 1 mm, a nozzle height of 1 mm, a print speed of 40 mm/s and a motor speed of 210 rpm. Post-processing effects on geometry, proximate composition and texture were compared using ANOVA (p < 0.05), showing that steaming offered the best overall balance of structural fidelity and acceptability. All post-processed samples were deemed acceptable based on sensory evaluation, confirming the potential for commercial application. This study demonstrates that plant-based, fiber-rich materials such as butterfly pea flower can be successfully formulated for use in FLM with appropriate process control and formulation strategies. Originality/value FLM introduces an innovative approach that uses a 3D printer to create edible items in a layered fashion, utilizing food inks such as chocolate, fruits and vegetables. This research demonstrates the successful development of nutritious plant-based foods using the FLM process, with a particular emphasis on producing foods that are well-received by consumers.