Investigation of Some Physical Properties of Two Varieties of Sweet Potato (Ipomoea batatas (L.) Lam)

Abstract

Physical properties of agricultural materials are essential in the development of machineries, equipment and devices. In this research, forty sample each of two unique varieties namely Jewel-orange flesh sweet potatoes (JOFSP) and Oriental-purple flesh sweet potatoes (OPFSP) physical properties were determined using standard methods and equations. The results show that JOFSP gave the mean length (110.68±24.59 mm), width(61.40±8.09 mm), geometric mean (39.72±8.19 mm), volume (187.78±73.85 ml), surface area (4950.00±203.32 mm2) and roundness (1.81±0.50) which were of higher values compared to that of OPFSP which gave the length (68.46±10.16 mm), width (59.32±5.82 mm), geometric mean (36.32±3.90 mm), volume (137.83±10.97 ml), surface area (4320.20±98.00 mm2) and roundness (1.41±0.30) respectively. JOFSP gave moisture content, thickness, mass, sphericity and true density of 58.00±10.17 %, 37.60±7.17 mm, 202.87±65.12 g, 0.35±0.08, and 1.17±0.27 g cm-3 which were of lower values compared to that of OPFSP which gave 79.32±3.84 %, 45.94±9.04 mm, 271.87±15.72 g, 0.53±0.08, and 1.89±0.14 g cm-3 for OPFSP respectively. The mean of the angle of repose and the static coefficient of friction considered for the three-separate surfaces namely plywood (9.35±2.87°, 0.17±0.05), stainless steel (8.50±3.50°,0.15±0.05) and galvanized steel (8.30±3.20°) of lower values for JOFSP compared to that of plywood which gave (11.80±2.25°, 0.21±0.04), stainless steel (9.90±2.02°, 0.19±0.05), galvanized steel (10.90±2.28°) for OPFSP while the coefficient static of friction of stainless steel for JOFSP gave a higher value of 0.20±0.13 compared to that of 0.17±0.04 for OPFSP respectively. These findings provide engineers with valuable information for designing different handling, grading, and drying systems for industrial processing.