Designing a novel composite thickener based on Tremella polysaccharide by comparing shear and extensional rheological properties with commercial products for dysphagia management

Dysphagia, difficulty swallowing that impairs bolus control and raises aspiration risk, affects many older adults, leading to malnutrition, pneumonia, and reduced quality of life. Available commercial thickeners typically require high powder doses and focus on shear viscosity, overlooking extensional properties essential for bolus cohesion. To bridge this gap, this study showed the development of a novel formulated product (FP), Tremella polysaccharide as the main ingredient owing to its excellent rheological properties, combining xanthan gum, sodium carboxymethyl cellulose and maltodextrin, optimized via a d-optimal mixture design to meet IDDSI levels 1–3. FP achieved target shear viscosities with 20–35 % less powder (0.4–1.0 % vs. 0.6–1.6 %), prolonged filament breakup to 420–580 ms (vs. 310–520 ms), delivered maximum extensional viscosities of 1200–1650 Pa·s (vs. 850–1350 Pa·s), and produced Trouton ratios of 35–40 (vs. 25–30), all indicating enhanced bolus integrity at lower dosing. Coupled with robust thermal stability and consistent rheological performance, FP represented a cost-effective, safer, and more functional solution for managing dysphagia.