Extrusion-Based 3D Food Printing of Gluten-Free Quinoa Biscuits: Formulation and Printing Parameter Optimization.

Extrusion-based three-dimensional (3D) printing technology offers a novel approach for developing nutritionally fortified, gluten-free cereal-based foods. Although quinoa is nutrient-dense, its lack of gluten network in traditional processing results in loose texture, however, 3D printing leverages material rheological properties to construct robust structures, effectively addressing this limitation. This study employed pure quinoa flour as the primary ingredient and conducted single-factor experiments to investigate the effects of sucrose, butter, and milk on dough rheology and texture properties. Response surface methodology was subsequently applied to optimize sensory quality, yielding an optimal formulation (10 g quinoa flour: 3.04 g sucrose, 3.09 g butter, and 6.84 g milk), with predicted and validated sensory scores of 84.4 and 83.7, respectively (p < 0.0001). On the basis of this optimal formulation, critical printing parameters were systematically optimized (nozzle diameter 0.8 mm, printing speed 40 mm/s, and infill density 65%). Using the optimized formulation and process, four three-dimensional models of varying complexity were successfully printed, demonstrating excellent shape retention and dimensional accuracy post-baking. This study confirms that quinoa is a promising gluten-free food ink with superior 3D printability, establishing a technological foundation for personalized manufacturing of healthy grain-based snacks.