The use of dextran in 3D printing for dysphagia foods: Relationships between its structure and physicochemical properties

Novel naturally sourced polysaccharides are gaining attention for their safety and improvement in food texture. This study investigated the correlations between the structural characteristics and physicochemical properties of dextran GS128 derived from Leuconostoc citreum SH12, and assessed its applicability in three-dimensional (3D) printed whole grain and legume-based (whole grain oat, chickpea and soybean) foods designed for dysphagia patients. The findings revealed that GS128 had a non-crystalline amorphous nature and high thermostability, suggesting its food processing potential. GS128 aqueous solution showed shear thinning and elastic gel behavior, and excellent thixotropic and structural recovery properties, and their effects were positive dose-dependent at the concentration of 4∼10 wt%, which were determined by its nearly linear structure mainly composed of 87.74% α-(1 → 6) linkages with a high molecular weight of 3.02 × 10⁸ Da. Moreover, the addition of 4∼10 wt% GS128 not only retained the shape of 3D printed whole grain and legume food, but also improved the swallowability by 33.26–74.60% compared with food without GS128, indicating the usage potential for dysphagia people. Overall, GS128 as a texture modifier has significant potential for application in the food industry, especially in the development of 3D-printed dysphagia diets.