| Abstract: | A comparative investigation of the fundamental and derived properties of starches from some species of yam (Dioscorea spp.) was conducted with a view to establishing their suitability as excipients in tablet and capsule formulations. Variations were observed in the mean granular diameter of the starches obtained from the different Dioscorea species. Granular diameter ranged from 5.4 µm (Chinese yam) to 34.5 µm (Round leaf yellow yam). Chinese yam and Bitter yam had the highest specific surface area (625.91 m2/kg and 258.76 m2/kg, respectively) while Round leaf yellow yam and Negro yam had the lowest (117.4 m2/kg and 154.34 m2/kg, respectively). Chinese yam had the lowest granular volume (6.00 µm3), surface area (5.67 µm2) and granule surface‐mean diameter (6.74 µm), while Round leaf yellow yam had the largest mean granular diameter, highest granular volume (35.2 µm3), surface area (34.8 µm2) and granule surface mean diameter (35.88 µm). Particle size distribution plots of Chinese yam, Round leaf yellow yam and Negro yam displayed a Gaussian size distribution pattern while Bitter yam displayed a negatively skewed distribution. The variations observed in the granular size and shape may influence the observed derived properties of the starches. |
