TOMATO PACKING LINES STUDIES WITH AN INSTRUMENTED SPHERE IN BRAZIL

Abstract

Fresh market tomatoes in Brazil are mainly classified and sorted by hand in the field, but increasingly these operations are performed in packinghouses using machines. The goal of this research was to determine the frequency and intensity of impacts in nine commercial tomato packing lines; three packing lines using locally built equipment, three using mixed lines (nationally built receiver, washer and sorter, and an imported classifier), and the other three using only imported equipment. An instrumented sphere (IS) Techmark, Inc., Lansing, (70mm) was used to measure impact intensities at each transfer point during packing. Impacts were measured as maximum acceleration (MA) in G (Gravity=9.81 m.s 2 ) and velocity change (VC) in m.s. The IS was placed on the top of plastic boxes, which were loaded manually. Subsequent transfer points on the packing line were sequentially measured until packing was finished. The IS was carried with the fruit over one or more transfer points while the elapsed time was recorded at each point using a stopwatch. The threshold on the IS was set to record impacts from 15 to 500G. The means of the 8 maximum levels were determined for each transfer point (MA and VC) since these parameters most accurately described impact intensities. Scatter plots of MA versus VC and MA versus transfer points were made for all impacts at each handling operation. For all packing lines the highest G values were found in the initial operations, when the operators drop the boxes in the packing line, and in some cases were close to 300G. Locally built packing lines showed higher MA values than those found in other packing lines.