Particle agglomeration of gum mixture thickeners used for dysphagia diets

Among various food gums, xanthan gum (XG), guar gum (GG), and carboxymethyl cellulose (CMC) are commonly used as main ingredients of commercial food thickeners for the management of dysphagia. In this study, the physical and rheological properties of XG and gum mixture powders (XG/GG and XG/GG/CMC) agglomerated by a fluidized bed agglomerator were investigated. Agglomerated XG/GG mixture showed the lower Carr index and Hausner ratio, indicating a better flowability and lower cohesiveness than the other samples. The viscosity values of thickened beverages, except for thickened water, prepared with the agglomerated XG/GG mixture were higher than those prepared with the agglomerated XG alone and XG/GG/CMC mixture. Storage modulus (G') values of thickened milk prepared with XG alone were significantly higher than those of gum mixtures. However, the loss tangent values of the thickened liquids prepared with XG alone were considerably lower than those of the liquids prepared with gum mixtures, demonstrating that the elastic property of thickened liquids decreased with the addition of GG and CMC. These results suggest that the physical and rheological properties of agglomerated gum powders were strongly influenced by the type of gum comprising the food thickener and the type of dispersing medium characterizing the thickened liquids.