Determination amount of pear bruises due to wide edge pressure via CT scan method and relation them with some physical properties pear

The study of the relationships between physical properties such as mass, volume and size of fruits is very important.In this research via CT scan, the relationship between physical properties of pears and storage times with bruise due to the loading force was investigated. Before loading and storing, 50 pears were examined using CT scan and 27 pears with zero bruise percentage were selected. 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, then selected pears were subjected to quasi-static loading with a thin edge pressure with three forces of 70, 100 and 130 N and 5, 10 and 15 d storage was used to investigate the effect of forces on pears. Then, after 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 and equivalent diameter, spherical coefficient and aspect ratio with the bruise percentage. Also a direct and unreasonable relationship between the level of the surface area and the percentage of bruising. Overall, it was found that, the pears have a higher surface area, the higher the percentage of a bruise.