Moisture Sorption Characteristics of Several Food Fibers

Adsorption behavior of microcrystalline cellulose, guar gum, wheat bran and oat bran were compared at 4, 25, and 37°C. Guar gum adsorbed the most water and microcrystalline cellulose adsorbed the least. Adsorption abilities of oat bran and wheat bran were similar at low and intermediate water activity levels. However, wheat bran was able to adsorb more moisture in the high water activity regions of the isotherm. Of the four fibers studied, particle size reduction had the greatest effect on sorption properties of wheat bran, in part, due to the reduction of surface area available for binding at the monolayer.