For all drying methods, the bulk density of mango powders increased and their porosity decreased with decreasing particle size (Fig. 5 and Fig. 6). These results may be attributed to the decrease in the inter-particle voids of smaller sized particles with larger contact surface areas per unit volume. Similar observation was reported for bulk density of ginger powder at different particle sizes (Xiaoyan, 2008). It was also consistent with the explanation by other authors that powder characteristics such as particle size may result in significant changes in bulk density and porosity (Barbosa-Canovas et al., 2005).