The effect of moisture content on the properties of gravity and frictional of three varieties pistachio

Physical properties of agricultural crops are important to design of milling، planting and harvesting machines and also for reducing losses and safe quality of crops along to post harvest stage. In this study، some physical properties of three common varieties pistachio nut (i. e. Fandoghi، Badami and Akbari) including of volume، bulk density، true density، porosity and static coefficient of friction were determined at five level of moisture content (35، 30، 25، 20، 15% w. b.). Then effect of pistachio nut moisture content was investigated on them. Results showed that with decreasing of moisture content of pistachio nut volume، bulk density، true density and static coefficient of friction were decreased while porosity was increased. At all pistachio nut moisture content levels and contact surfaces، the most static coefficient of friction allocated to black sheet and the lowest static coefficient of friction allocated to aluminum contact sheet.