Physical and rheological properties of xanthan gum agglomerated in fluidized bed: Effect of HPMC as a binder.

Physical and rheological properties of agglomerated xanthan gum (XG), commonly used as a food thickener for the management of the patients with dysphagia (swallowing difficulty), were investigated at different concentrations (0, 2, 4, and 6% w/w) of hydroxypropyl methylcellulose (HPMC) as a binder in the fluidized bed agglomeration process. Flow characteristics of agglomerated XG powder were evaluated using Carr index (CI) and Hausner ratio (HR). The agglomerated XG powders obtained by HPMC binder exhibited a better flowability and higher porosity than the agglomerated powder without binder due to the size enlargement of XG powder. Dynamic moduli (G' and G") of agglomerated XG powders at 2% and 4% HPMC were significantly higher than those of other powders. The tan δ values of agglomerated powders with HPMC binder were much lower than that of an agglomerated powder without HPMC, indicating that their elastic properties were enhanced because of the addition of HPMC binder. Results suggest that the use of HPMC in agglomeration process could considerably enhance the flow characteristics and rheological properties of XG powder.