3D printing of ascorbic acid-rich protein-starch gels for dysphagia diets: texture, nutritional and bioactive properties

Dysphagia affects the ability to safely consume regular-texture foods, requiring the development of modified-texture products with adequate nutritional and structural properties. 3D printing can be used to tailor the texture, and shape of the food, allowing the development of customized foods that meet with the need of people with dysphagia. Therefore, this study evaluated the texture, nutritional and bioactive properties of ascorbic acid-rich 3D-printed gels for dysphagic diets, using acerola pulp, native or Dry Heating Treatment (DHT) maize starch and concentrated pea protein as gelling ingredients. The gels were prepared using 5 %, 10 %, and 15 % of gelling ingredients, with starch:protein ratios of 100:0, 50:50, and 0:100. Gels were evaluated for 3D printability (under 40–100 % infill rates) and suitability for dysphagia (texture), based on IDDSI criteria. The selected gels were evaluated according to ascorbic acid content and antioxidant capacity (using both FRAP and ABTS methodologies). Formulations with 15 % ingredients starch-protein ratios (50:50) exhibited smooth extrusion, good shape fidelity, and structural stability after printing. Regarding nutritional content, the starch-containing gels preserved ascorbic acid content (up to 94.3 % compared to fresh pulp), while the protein-containing formulations showed slightly greater losses (up to 27 %). However, the protein-containing formulations showed higher antioxidant capacity, indicating the contribution of bioactive compounds from the protein. In conclusion, this work demonstrated desirability ranges in formulation and processing conditions to produce gels suitable for both 3D printing and dysphagic diets, obtaining gels with the potential to be used as ascorbic acid supplements. These results highlight the potential of combining bioactive acerola-based ingredient modified starch and vegetable protein to produce printable, functional foods/supplements for individuals with dysphagia. • Protein gels were printed with 15 % gelling ingredients. • Starch gels could be printed with 10 % of the content of gelling ingredients. • A Pea protein/starch blend performed best for dysphagia diets. • Starch-based formulations retained high levels of ascorbic acid. • Protein-containing gels showed higher antioxidant activity.