Some Mechanical Properties of Soursop Seeds and Kernels at Different Moisture Contents under Compressive Loading

Soursop seed is an economically important oil seeds which contains about 40% oil useful in the chemical industries. The present prevalent drudgery associated with low output in its manual dehulling and oil extraction processes, has necessitated the need to study its mechanical properties to enhance the effective mechanization of its handling and processing unit operations. This study therefore, aimed at evaluating some mechanical properties of soursop seeds and kernels. The properties (rupture force and energy, bio-yield force and energy, deformation and hardness at seed vertical and horizontal direction and kernel resting position) were determined using Instron Testing Machine. Within moisture content of 8.0 to 32.5% (db), rupture force, rupture energy, bio-yield force, bio-yield energy, deformation and hardness ranged from 43.98-20.0 N, 40.0-188.0 N.mm, 41.5-22.3 N, 6.73-1.89 N.mm, 1.89-3.58 mm and 23.27-5.59 N/mm, respectively, at the seed horizontal direction, from 576.8-787.7 N, 512.0- 1488.6 N.mm, 144.9-1751.7 N, 41.0-246.0 N.mm, 2.19-4.42 mm and 29.1-35.8 N/mm, respectively, at the seed vertical direction and from 576.8 to 787.7 N, 512.3 to 1488.6 N.mm, 44.9 to 1751.7 N, 6.73 to 1.8 N.mm, 2.19 to 4.42 mm and 29.31 to 31.66 N/mm at the kernel resting position. The study established that the mechanical properties of soursop seeds and kernels depend on moisture content (p≤0.05), which is useful for engineers in the development of soursop seed dehuller and oil-expeller.