Abstract: The particle structure, flowability and their relationship between dietary fiber powders from various sources (mushroom, cereal, fruit and vegetable) were comparatively investigated in the present work. The results indicated that there were large differences among the particle sizes (D10, 130.3–9.0 μm), specific surface areas (2.06–0.18 m2/g), pore volumes (13.15–0.37 cm3/g), pore diameters (61.46–4.45 nm) and angles of repose (32.01°–56.85°) and slide (21.90°–54.94°) of forty dietary fiber powders, which were not significantly dependent on the source. In terms of pore diameter, all the dietary fiber powders except that from sugarcane were classified as mesoporous materials. Correlation analysis revealed that particle size was negatively correlated to specific surface and span while pore volume was positively correlated to specific surface and pore diameter. More importantly, the flowability of dietary fiber powder was significantly correlated to its particle size, specificity and pore volume, but it was not tightly correlated to its pore span and volume.

Key words: dietary fiber, powder flowability, particle size distribution, pore structure, correlation analysis