The effect of drop height on bruising of selected apple varieties

• Dissipated energy and maximum force were best correlated with apple bruise volume.
• The soft variety ‘Freedom’ was characterized by the largest bruise surface area.
• The hard variety ‘Rajka’ was characterized by the largest bruise depth.
• 0.25 m s−1 was the maximum safe velocity at which bruises did not develop.

This paper presents an analysis of fruit impact in time and the results of the relationships between the bruise size and various impact parameters. The measuring device allows simultaneously analysis of the three basic quantities: impact velocity, rebound velocity and force response in time, and testing the momentum conservation law for a body such as an apple. In the experiments, the impact velocity 0.25 m s−1 was the maximum velocity at which bruises for all tested apple varieties did not develop. The parameters which were the most strongly correlated with apple bruise volume were maximum force response and dissipated energy, which can be used to predict direct impact effects.