Abstract: The viscosity of gum-thickened foods, non-Newtonian fluids with pertinent high viscosity, is critical for managing dysphagia. The thickening effect of the polysaccharide hyaluronan on enteral nutritional suspensions containing pea protean and soybean oil were investigated by rheological measurements such as flow properties, viscoelasticity and viscosity as a function of shear rate and shearing time. The experimental results indicated that the unthickened sample was a Newtonian fluid with a very low viscosity (only ca. 0.010 Pa·s) which could not meet the requirement of safe swallowing. Hyaluronan had an excellent thickening ability, the initial viscosity of the thickened suspension was up to 8 Pa·s at a hyaluronan concentration of 0.5%, and the thickened suspension showed adjustable viscosity and viscoelasticity and shear thinning behavior, demonstrating the promising application of hyaluronan in dysphagia diet management.

Key words: hyaluronan, thickening, nutritional preparation, dysphagia, rheology