The aim of this work is to determine the physical and mechanical properties of three varieties of potatoes (Criolla, Pastusa and Capiro), in order to use them in the design and management of sowing, harvest and postharvest machines and adopt storage time of potato. Some of the physical properties like: axial dimensions, sphericity, roundness, repose angle, apparent density, real density and porosity were measured, as well as the mechanical properties like: compression, punction and cut strength and friction coefficient. The factor of variation such as size and the sampling time (every 15 days during 3 months) were involved for each variety of potato using a completely random block design. The data were analyzed statistically through the analysis of variance by the Duncan´s method. The physical properties varied in similar way, the sphericity and roundness increased when the size reduced. The porosity is higher than 48% while the repose angle obtained is characteristic of approximately spherical shapes for three analyzed varieties. The principal influence over the variability in the mechanical properties is the change in the moisture content, besides, a turgency loss was observed during the storage time that provides more elasticity in the tuber which permit the tuber to bear higher loads. The Criolla variety showed a strength between three to five times more than Capiro and Pastusa varieties in cut, punction and compression test.
mechanicals properties; physical properties; Solanum tuberosum; design parameters; postharvest management
