Application of sorting dependent criterias in determination of volume and area bruising of “Golab-Kohanz” apple in Iran

Apple fruits are subjected to different loading damage from harvesting to supermarket shelf. Bruising has been attracted many researchers as one of the most important damage criteria. In this research, the effects of some factors such as counter-face material, drop height and linear velocity of apples (conveyor speed) were investigated. Influence of these factors on bruising of “Golab-Kohanz” variety was analyzed by a Completely Randomized Design (CRD) with factorial test at three levels of drop height (10, 20 and 30 cm), conveyor speed (0.05, 0.1 and 0.15 ms- 1) and four counter-face materials (wood, steel, plastic and cardboard). Tests were conducted at three replications with 108 treatments. Analysis of variance results showed that the effects of drop height and counter-face material on bruising area at 1% level was significant while bruising volume only affected by contact surface material (P<0.01). Mean comparison test indicated that there was no significant difference among levels of conveyor speed on the area and volume bruising. Also, there was no significant difference among levels of drop height on volume bruising while it was significant on the area bruising. Steel and wooden material had no significant effect on the area and volume bruising but their differences with plastic and cardboard were significant. Therefore, drop height and counter-face material must be considered in designing the apple processing systems.