Deformation and Strength Properties of Potato with Different Degree of Fixity
Properties of potato depend on the variety, agrochemical and soil and climate conditions, the way and duration of storage period before processing at a plant. Energy consumption for processing of fresh potato is much lower than for crushing of faded tubers after the long storage, deformation and strength properties of which change significantly decreasing the crushing efficiency. The submitted experimental compression data of potato tuber samples with obtained charts of their destruction enable to estimate energy consumption for potato crushing while processing fresh raw materials and faded potato. The test technique was based on GOST 25.50397 for tubers with different hardness. The destruction of samples happens according to a fragile type regardless of tuber hardness on the even surface directed at the angle 45 degrees to the sample axis. The hardness degree of tubers does not influence the material strength point and the relative value of the destruction deformation. Sigma(MS) is about 0.5 MPa and epsilon(max) is 0.27. However, it influences the initial stage of samples compression, which has the flat part growing with the increasing degree of the tuber decay. After the flat section there is the main part of charts which can be described by linear functions sigma = a + E * epsilon. The E value depends on the degree of tuber decay and therefore can be called as a conditional module of a longitudinal elasticity. With the increase in the level of tuber decay E value grows. To decrease the energy consumption for potato processing it is necessary to use the efficient modern methods for its storage and to reduce the duration of a production season.