Effect of storage time on some quality parameters (physical and mechanical) Valencia orange

External and internal changes in fruits during storage time are affected by the various factors that some of them can by studied by measuring the qualitative parameters (physical and mechanical). The effects of storage time on some physical and mechanical properties of Valencia orange were investigated. The experiment was performed as factorial based on completely randomized design. Analysis of experimental results showed a significant effect of storage time on all the physical parameters of Valencia orange. With increasing time، the true density of oranges increased while other physical parameters decreased. Rind ratio and moisture content increased and true density decreased with increasing the size of fruit. Also the effect of storage time and fruit size on the rupture force and deformation was significant at the level 0. 01. The mean failure load for 2، 32 and 62 days storage were obtained 206. 05، 139. 64 and 221. 07 N، respectively. Rupture force and deformation values were followed by increasing fruit size.