Advancing dysphagia-oriented multi-ingredient meal development: Optimising hydrocolloid incorporation in 3D printed nutritious meals

Dysphagia (DP) is a growing health concern in today's ageing population, leading to high demand for DP-oriented food. 3D printing is a promising novel technology for developing new attractive and appetising products. Therefore, we aimed to develop a 3D-printed shaped meal, to serve as a nutritious DP-oriented food. The texture was modified with the addition of different thickeners: 2.0% (w/w) k-carrageenan gum (KC) and 1.0 or 1.5% (w/w) guar gum (GG), xanthan gum (XG), locust bean gum (LBG), and gum arabic (GA). Upon characterising and mapping the rheological behaviour involved in extrusion-based 3D printing, the higher concentrations of GG, XG, LBG and GA were found to significantly increase the yield stress and apparent viscosities of the ink formulations. In addition, the colour attributes were examined, while a low population of total viable bacteria (TVC) was observed. The DP-oriented formulations had high fibre content, regulating bowel function and glucose metabolism in the elderly. According to the International dysphagia diet standardisation initiative (IDDSI), KC/XG1 and KC/LBG1 were classified as level 5 indicative of minced and moist dysphagia diet, while KC/GA1, KC/GA1.5, KC/XG1.5, and KC/GG1.5 were classified as level 4, that can be bitten or chewed if the tongue control is reduced. All ink formulations demonstrated high printing precision with excellent self-supporting capability and smooth surface texture that were easy to extrude and print complex samples. This study provides valuable insights into addressing dysphagia by developing a nutritious meal using 3D printing.