Comparisons of the rheological, tribological and sensory properties of sodium alginate with commercial thickeners at different IDDSI levels for dysphagia management

This study comprehensively investigated the shear and extensional rheological, tribological and sensory properties of sodium alginate (SA) with varying molecular weights (SA-1: 177 kDa, SA-2: 244 kDa, SA-3: 392 kDa), in comparison to commercial thickeners (CMC, κ-CG, XG) at IDDSI level 1–3. The results indicated that significant variability in the concentrations required to achieve the same IDDSI level across the six polysaccharides. The oscillatory rheology analysis suggested that SA-1, SA-2, SA-3 and CMC primarily exhibited viscous, liquid-like behavior across all three IDDSI levels, while XG consistently exhibited elastic and weak-gel behavior. Besides, the tribological properties showed that all SA samples maintained relatively low friction coefficients across all IDDSI levels when compared to the commercial thickeners, demonstrating a better lubricating performance of SA. Moreover, the sensory evaluation confirmed that SA samples had higher smoothness perception than XG. Consequently, developing dysphagia thickeners must address both rheology, sensory appeal and oral comfort.