Physical Properties of Roselle (Hibiscus sabdariffa L ) Seed


  • Adeleke Isaac Bamgboye University of Ibadan,Nigeria
  • Ismaila Oyebola Adejumo Federal Poythechnic, Bida


The physical properties of Roselle seeds were determined at different moisture contents. The seeds were ground and classified into two particle sizes. The fine and coarse samples were conditioned by adding calculated amount of distilled water to different moisture contents from the initial moisture contents of 4.4 % and 5.14 %, respectively. The moisture contents were 4.4, 6.4, 8.4, 10.4 % for fine and 5.14, 7.14, 9.14, 11.14 % wb for coarse samples. The properties were determined using ASAE standards. The mean values of the physical properties of the seeds were determined as 4.75-4.85 mm length, 4.15-4.26 mm width, 2.62- 2.67 mm thickness, 3.73-3.83 mm geometric mean diameter, 648.31-619.14 kg/m3 bulk density, 20.13°-24.85° angle of repose, 17-18.5 mm2 surface area, 52.6-58.3 % porosity, 1367.0-1487.4 kg/m3 true density, 29.7-40×10-6 m3 volume, 5.8-7.1 m/s terminal velocity, 1.36-1.44 specific gravity. The coefficient of static friction was measured on mild steel (0.23-0.32), plywood with the grains parallel to the direction of motion (0.38-0.45) and glass (0.22-0.30). The physical properties of the seeds were found to increase as the moisture content increases with the exception of bulk density that decreased.

Author Biographies

Adeleke Isaac Bamgboye, University of Ibadan,Nigeria

Agricultural and Environmental Engineering Senior Lecturer

Ismaila Oyebola Adejumo, Federal Poythechnic, Bida

Dept. of Agricultural Engineering







VI-Postharvest Technology and Process Engineering