Computer Simulation of Bruise in Red Delicious Variety of Apple Fruit

Large sums of fruits are annually wasted due to mechanical damage and bruise inflicted upon them during harvesting, handling, storage and packaging. The research which has been done to analyze the mentioned processes mostly used practical operational techniques with the results being applicable in certain defined conditions. The aim of this research was to develop computer models for an optimization and design of postharvest processes and equipment with a minimum incidence of bruise. Two experimental test series were conducted on Red Delicious variety of apple. The first test series were performed to determine the geometrical dimensions and mechanical properties of texture, as well as other parameters needed to attain accurate finite element models. The second ones were performed to determine pressure distribution in contact areas and to provide force-deformation data for validation and a comparison of results in simulation models. Mean curvature at the middle part of the apple fruit was found as 61.43 mm, that is 3.7 times larger than curvature at the top and lower parts of the fruit. Also, the mean failures of stress and strain were obtained 282, and 0.071 kPa, respectively. The simulation results revealed that there existed a significant difference between the results of elastic model and those of the experimental data, but there was no significant difference observed (at 1% level) between the elastoplastic model and the experimental data. Maximum compression load for Red Delicious variety of apple, using the simulation model was found equal to 32 N that well agreed with the other published research results.