Physical properties of African star apple fruits and seeds

Abstract

This research examines the physical properties of African star apple (Chrysophyllum albidum) fruits and seeds. The dimensions were measured with vernier calliper and the dimensional properties were computed using appropriate equations. The densities, porosity, angle of repose and coefficient of friction on three material surfaces were determined with standard methods from literature. The result of the study showed that the average major, intermediate and minor dimensions were 47.95 mm, 43.70 mm and 41.35 mm respectively for the fruits, and 26.05 mm, 15.12 mm and 6.07 mm respectively for the seeds. The volume, shape index and one thousand weight of fruits were obtained as 40.61 mm3 , 0.95 and 48.34 kg respectively whereas those of the seeds were obtained as 1.69 mm3 , 0.95 and 1.28 kg respectively. The true density, bulk density and porosity of the fruits were found to be 1710 kg/m3 , 1550 kg/m3 and 52.63 percent respectively, while that of the seeds were found to be 950 kg/m3 , 570 kg/m3 and 40.25 percent respectively. The sphericity obtained for the fruits and seeds were 0.94 and 0.55, respectively. Angle of repose was found to be 3.02o and 13.50o for the fruits and seeds, respectively. Coefficients of friction on plywood, mild steel and galvanized steel were 0.30, 0.24 and 0.20 respectively, for the fruits and 0.52, 0.46 and 0.39 respectively for the seeds. The empirical data from this study will aid researchers in the design and development of postharvest systems for the African star apple fruits and seeds postharvest operations.