Indagine sul danneggiamento meccanico delle arance nelle linee di lavorazione

The present note refers to the synthesis of a long-term research on the mechanical damage of the oran-ges during post-harvest processing, using the Instrumented Sphere IS100 as a main tool of investi-gation.Preliminary laboratory tests on the IS100 pointed out a good repeatability of the measurements, charac-terised by a CV of 11.8% for the peak acceleration and of 4.6% for the velocity change, and a notable linearity of its response with respect the drop height.The use of the IS100 in a packing-line pointed out that the end of the elevators (69 g, 77 g), preselection (70 g) and defoliation (61 g) are the places in which are present the greatest solicitations in terms of avera-ge peak acceleration; that drying (A = 296 g, v = 2.00 m/s), calibration (A = 263 g, v = 2.31 m/s) and fee¬ding (A = 234 g, v = 1,83 m/s) are the process in which are present the greatest solicitations in terms of maximum peak acceleration; that elevations (9.4), selection (7.5) and feeding (6.6) are the processes that produce the greatest average number of impacts with peak acceleration greater than 19 g, selected as recor-ding treshold; that the sphere, and than an orange, receives on average 61 impacts of 52 g mean peak acceleration from its introduction in the line up to the packing; and that repeated impacts in a same area of the oranges’ epicarp are intrinsic to the packing pro-cess.The damage tests of the oranges underlined that single impacts hardly give rise to remarkable altera-tions from the commercial point of view, at least with energies comparable with those present in the lines; that repeated impacts on the same area of the epicarp, also from modest drop height (10 cm), are able to cause remarkable alterations; that the percentage of altered oranges grows with respect to the grow of the impact energy; that, total supplied energy being equal, tests with a higher impacts number are more injurious rather than those with a higher drop height; and that the losses of weight after one and two weeks from the tests don’t seem to be correlated with the percentage of damaged oranges.