Mechanical damage to oranges caused by repeated impact against steel

This paper reports the results of a study on damage to oranges (cv Tarocco) in consequence of repeated impacts, that simulate the mechanical stresses to which the fruit is exposed during post-harvest in packing lines. To this end, some oranges were subjected to impacts against a steel surface from drop heights comparable with those observed in packing lines. The results show that the impacts considered here do not determine statistically significant differences in either the percentage or the absolute loss of mass, in the percentage of energy absorbed or in the consistency of the fruit, in that no such tendency is to be found when the number of impacts or the drop height is increased. An overall comparison of the oranges subjected to impact and the control shows that only the absolute loss of mass is statistically lower for the control. Repeated impacts above all bring about external alterations, causing the softening and flattening of the impacted area, phenomena often associated with oleocellosis and occurring much less frequently in the control. These alterations increase as the impact energy is increased and, if the energy is the same, a greater number of impacts is always more dangerous than a greater drop height.