Bruise damage is a major cause of fruit quality loss. Bruises occur under dynamic and static loading when stress induced in the fruit exceeds the failure stress of the fruit tissue. Statistical bruise estimation models were constructed to calculate Golden Delicious apple bruise volume with respect to fruit properties. Approach: The regression models were built based upon impact force and impact energy as main independent variable with other parameters including fruit curvature radius, temperature and acoustical stiffness. An instrumented pendulum was constructed as a tool to perform three levels of controlled impact on apple fruit. Results: Significant effects of acoustical stiffness, temperature and the curvature radius and some interactions on bruising were obtained at 5% probability level with the coefficient of determination of 0.93 and 0.98 for force model and energy model respectively. Conclusion: It was demonstrated that increasing the temperature and curvature radius and lowering acoustical stiffness will reduce the bruise damage of the golden delicious apple fruit.

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