Investigating rheological properties and 3D printability of carbohydrate, protein, and fat-rich food inks for dysphagia-friendly diets

3D food printing (3DP) offers new opportunities to produce nutritious, visually appealing foods tailored for individuals with dysphagia, who require safe, texture-modified diets. However, there is a crucial lack of diverse food sources and balanced nutrition in current dysphagia-friendly 3DP foods. Therefore, in this study, we investigated the rheological and textural properties and printability of independent carbohydrate-based, protein-based, and lipid-based food “inks” to enhance the nutritional diversity of 3D printed foods. Results indicated that the macronutrient concentration significantly influenced all inks' printability, rheological, and textural characteristics. Additionally, incorporation of food hydrocolloids improved the viscoelasticity, yield stress, and printability of Mashed Potato (MP), Pea Protein Isolate (PPI), and Faba Bean Protein (FBP) inks. However, at higher macronutrient concentrations (>25 %), the addition of hydrocolloids was detrimental to the yield stress and texture of the carbohydrate and protein inks, resulting in a decline in print accuracy (print deviation (PD) > 15 %). Ultimately, food inks which possessed lower apparent viscosity (280–400 Pa.s) and hardness (4–8 N), along with high elastic modulus (G') (8000–20,000 Pa), yield stress (400–800 Pa), and cohesiveness (0.6–0.8) resulted in 3D printed structures with high resolution, smooth textures, and strong self-supporting ability. MP, PPI, and Sunflower oil oleogels demonstrated superior print accuracy and mechanical stability among the tested inks. These findings demonstrate that rheological optimisation is critical for designing 3D-printed dysphagia foods and highlight the potential of macronutrient-rich food inks for clinical and aged-care dietary applications. • Macronutrient-rich inks were characterised for utilisation in 3D food printing. • Macronutrient concentration was related to both rheology and texture. • The addition of gums improved viscoelasticity, texture and printability. • Inks with superior printability can potentially be utilised in dysphagia diets.