Selected engineering properties of tiger nut as a function of moisture content and variety

Some physical and mechanical properties of two tiger nut varieties (Sariseker and Balyumru) were determined at four moisture contents. Physical properties including length, width, thickness, geometric mean diameter, mass, 1000-tuber mass, bulk density, tuber density, surface area, terminal velocity, angle of repose, porosity, and friction coefficient were affected by moisture content at a 1% probability level, excluding sphericity. All parameters decreased with a decrease in moisture content except tuber density, porosity, and firmness. Variety only had a statistically significant effect on width, geometric mean diameter surface area, and terminal velocity at different probability levels. Force, deformation, firmness, energy absorbed, and power requirement, which were investigated as mechanical properties, were also affected by moisture content at a 1% probability level. It was also found that the variety and loading position had no significant effect on firmness and energy absorbed, respectively. Varieties showed differences in terms of 1000-tuber mass, sphericity, terminal velocity and angle of repose, length, geometric mean diameter, surface area, porosity, force, and energy absorbed at different probability levels.