Determination of Bruise Incidence of Pomegranate Fruit under Drop Case

The incidence of fruit postharvest losses and waste due to mechanical damage during handling is a major problem in the fresh produce industry. The objectives of this study were to investigate the impact of bruise damage susceptibility of pomegranates during harvesting, sorting, packaging, and transportation. A drop testing technique was used, as it was thought to be the most realistic simulation of what would actually happen to the pomegranate. Four different counterfaces, namely cardboard, rubber on steel (to simulate the rubber of a conveyor), wood, and methacrylate (to simulate retail polyethylene plastic bags) were used in the drop tests as impact surfaces. Results showed that the incidence to bruise damage of the pomegranates were affected by pomegranate cultivars, material counterfaces, and drop heights with Duncan’s Multiple Range test, p < 0.05. There was an approximately linear relationship between bruise volume and impact energy, with different gradients for each impact surface (Cardboard, rubber on steel, wood, and methacrylate showed a Pearson correlation of 0.989, 0.986, 0.990, and 0.993, respectively, with sig < 0.001). Based on the bruise threshold value (100 mm2), a critical drop height value for each impact material and pomegranate cultivar were estimated, in which average critical drop height value for cardboard counterface was greatest (24 cm) and for rubber on steel counterface was least (8 cm). The results obtained can be used by designers of packaging materials, processing plants, and handlers of fresh pomegranate fruits to reduce mechanical damage, especially those due to impact, and ensure good quality products.