This work presents the development of prebiotic food inks for 3D printing applications using Direct Ink Writing (DIW) technology. Apple powder, sourced from discarded fruit, served as the nutritional matrix and was characterized through proximate analysis (moisture, ash, proteins, and carbohydrates). Agavins were incorporated as a functional ingredient due to their prebiotic effect and compatibility with biopolymers such as sodium alginate and xanthan gum, which provide key structural and rheological properties essential for formulation. A mixture design with response surface methodology (RSM) was applied to optimize the formulation, using apparent viscosity as the response variable due to its influence on extrusion and the structural stability of the printed material. The optimized formulations were rheologically characterized through flow and oscillatory tests. The results indicated a favorable interaction among the biopolymers, which improved ink consistency. All formulations exhibited pseudoplastic behavior (flow index n < 1), with a consistency index ranging from 93 to 123 (power law model), evidencing shear-thinning behavior and adequate post-extrusion stability. In oscillatory tests, the inks exhibited gel-like solid behavior (G' > G'' in the linear viscoelastic region), suggesting good rigidity and mechanical strength. Yield stress ranged from 153 to 227 Pa, indicating suitable pressure for smooth and continuous extrusion during printing. This study demonstrates the potential of food inks formulated with apple powder and natural biopolymers to produce 3D-printed functional foods, with applications in functional foods and personalized nutrition.

The author Oscar Didier Rivas-Llamas thanks the Secretería de Ciencias, Humanidades, Tecnología e Innovación for the scholarship granted (No 4021475) for doctoral studies, and the Tecnológico Nacional de México (TecNM) for the financial support of the project 22616.25-P. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.