Effect of hot air temperature on mechanical properties of dried apples

Abstract The aim of this work was to determine the effect of temperature and water content on the mechanical properties of convection dried apples. Apples v. Idared were cut into slices and then air-dried at temperature in the range from 50 to 80 °C. Mechanical properties were measured by compression–relaxation test. Samples were investigated after drying and also after 5 weeks of storage over anhydrous calcium chloride at constant temperature. Analysis showed that the observed differences between compression–relaxation curves of apples dried at 50, 60 and 70 °C were not significant. Decreasing of water content caused an increase of force needed to compress dried apples. Drying at 80 °C affected the texture of dried apples much more in comparison to those obtained at lower hot air temperature. The use of suitable temperature and drying of apples to definite water content could be used to design the mechanical properties of the final product.