Deformation and Dehulling of Sponge Gourd (Luffa aegyptiaca) Seeds

Abstract

This work presents the compressive strength properties of sponge gourd (Luffa aegyptica) seeds to facilitate the design or adaptation of an appropriate dehuller. The sizes and shape indices of the seed and kernel, and the clearance of the kernel from the seed coat were determined. The seed samples were subjected to uni-axial quasi-static compression tests at 1.0 mm min−1 along the minor and the major axes. The fracture resistance, stiffness modulus, modulus of elasticity, toughness, and maximum elastic deformation of the seed were obtained from the force-deformation curve. The geometric mean diameters varied from 4.0 to 4.5 mm for the seed and 1.6 to 3.9 mm for the embedded kernel; while their corresponding sphericities were 0.64 and 0.62, respectively. The compressive strength of the seed varied with loading orientation. The seed exhibited larger deformation but lower stiffness along the major axis than the minor axis. The force required for rupturing the hull were 95 N along the major axis and 81 N along the minor axis; while the corresponding energy required were 95 and 40 mJ