Determination of the physical and mechanical properties of a potato (the Agria variety) in order to mechanise the harvesting and post-harvesting operations

Abstract

Studying the physical and mechanical properties of agricultural products has been the subject of criticism and discussion for many years already and has attracted the attention of many researchers. The physical and mechanical properties of agriculture products are the most important parameters in the design of agricultural machinery sorting systems, transmissions, processing and packaging systems. The potato is one of the most important agricultural products as a food resource. The aim of this research is to investigate the physical properties and mechanical behaviour of the potato due to its importance and the current inadequate information about it. In this research, some of the physical and mechanical properties of the potato were measured in standard conditions. The length, width, thickness, geometric mean diameter and arithmetical diameter, sphericity, surface area, aspect ratio, mass, volume, bulk density and the  projected mean area were included in the physical properties. The mechanical properties of the potato were determined by using a universal testing machine (MRT-5; Santam, Germany) with a uniaxial compression test. Then, the mechanical properties were measured with four repetitions. The physical properties of the potato such as length, width, thickness, mass, volume and geometric mean diameter had a direct relationship, while the density had an inverse relation to the size. The result of the mechanical properties of the sample, such as vertical stress, elasticity module, deformation energy, fracture force and deformation were obtained respectively as 0.34 MPa, 3.09 MPa, 892.02 J, 8.80 N and 207.22 mm. The comparison of the potato’s real volume with the standard shapes showed that the potato’s shape is similar to an oval due to the largest determination coefficient (R² = 0.86). The results of this research can be used for the design and optimisation of the processing equipment, as well as the transporting, sorting and packing of the potato crop.