University of Tehran Press Iranian Journal of Biosystem Engineering 2008-4803 50 2 2019 08 23 Determination of Pear Bruises Due to Impact Loading via Computed Tomography Scan Method and Relation Them with Physical Properties Pear Determination of Pear Bruises Due to Impact Loading via Computed Tomography Scan Method and Relation Them with Physical Properties Pear 451 462 72591 10.22059/ijbse.2019.255847.665052 FA Mohsen Azadbakht Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran 0000-0002-5726-9321 Mohammad Vahedi Torshizi Department of Bio-system Engineering, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran. Mohammad Javad Mahmoodi Department of Bio-system Engineering, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran. Journal Article 2018 04 22 In this research via CT scan, the relationship between physical properties of pears and storage times with bruise due to loading force was investigated. Before dynamic loading force and storing, 45 pears were examined using Scan CT and 27 pears with zero bruise percentage were selected  and dimensions of pears (length, width, thickness) were measured, then properties such as the equivalent diameter, geometric mean diameter, spherical coefficient, surface area and aspect ratio of calculus were calculated, next selected pears were subjected to dynamic loading with three  mass of weights 300, 350 and 400 g and  5, 10 and 15 days storage was used to investigate the effect of impact on pears. Then, after dynamic loading and storing, using the CT scan in each period of storage, the rate of pear bruise was calculated. The results of the experiments showed that there is an inverse relation between geometric diameter, arithmetic diameter, equivalent diameter and surface area with the bruise percentage. Also a direct and unreasonable relationship between the spherical coefficient and aspect ratio and the percentage of bruising was absorbed. Also, according to the results obtained for mass weighing 300 g or less in 5-day storage period, the amount of geometric diameter, arithmetic and equivalent diameter, spherical and aspect ratio on percentage of bruising were not significantly affected and percentage of bruising can be almost zero and with increasing amount mass weighing and storage, the above parameter's will affect the percentage of bruising. In this research via CT scan, the relationship between physical properties of pears and storage times with bruise due to loading force was investigated. Before dynamic loading force and storing, 45 pears were examined using Scan CT and 27 pears with zero bruise percentage were selected  and dimensions of pears (length, width, thickness) were measured, then properties such as the equivalent diameter, geometric mean diameter, spherical coefficient, surface area and aspect ratio of calculus were calculated, next selected pears were subjected to dynamic loading with three  mass of weights 300, 350 and 400 g and  5, 10 and 15 days storage was used to investigate the effect of impact on pears. Then, after dynamic loading and storing, using the CT scan in each period of storage, the rate of pear bruise was calculated. The results of the experiments showed that there is an inverse relation between geometric diameter, arithmetic diameter, equivalent diameter and surface area with the bruise percentage. Also a direct and unreasonable relationship between the spherical coefficient and aspect ratio and the percentage of bruising was absorbed. Also, according to the results obtained for mass weighing 300 g or less in 5-day storage period, the amount of geometric diameter, arithmetic and equivalent diameter, spherical and aspect ratio on percentage of bruising were not significantly affected and percentage of bruising can be almost zero and with increasing amount mass weighing and storage, the above parameter's will affect the percentage of bruising. https://ijbse.ut.ac.ir/article_72591_2fc174708d449ce2801b2216593ca986.pdf