Agglomerate Growth of Xanthan Gum Powder during Fluidized-Bed Agglomeration Process

Xanthan gum (XG) powder was agglomerated via a fluidized-bed agglomeration process using water and maltodextrin (MD) binder solution, after which the products were examined. The agglomerated XG samples were collected every 10 min during agglomeration (50 min) to characterize particle growth behavior. Here, we investigated the particle size distribution, morphological characteristics, and rheological properties of agglomerates obtained at different agglomeration times. The particle size gradually increased with agglomeration time from 0 to 50 min. The porous agglomerates showed rapid growth after 40 min. The particle size of the final products tended to decrease in the dry phase for 10 min due to particle attribution during drying. Using MD as a binder solution instead of water resulted in larger XG particles. The dynamic moduli (G' and G″) of the final product with water binder were higher than those of the native powder, whereas those of the final product with MD binder solution were lower. The G' values of the agglomerates with MD increased gradually with agglomeration time. Native XG powders exhibited small and dense particles with a smooth surface, whereas the XG agglomerates had large and porous particles with rough surfaces and became more irregular and rougher as the agglomeration progressed.