Vibration of Fresh Fruits and Vegetables During Refrigerated Truck Transport

R. T. Hinsch, D. C. Slaughter, W. L. Craig, J. F. Thompson
1993 Transactions of the ASAE  
Fresh fruits and vegetables experience losses enroute to market that are caused by mechanical injuries. Past studies have indicated that transit vibration contributes to this loss, and may be more important than impacts as a source of damage. In cross-country tests of cherries, nectarines, and pears in semi-trailers equipped with steel-spring suspension systems, highest Power Spectral Density (PSD) levels were found at about 3.5 Hz. In this study, PSD is used to mean acceleration spectral
more » ... tion spectral density. Other frequencies with high PSD levels were 9,18, and 25 Hz, Similar results were found in tests with fresh tomatoes. However, in trailers equipped with an air-ride suspension and loaded with tomatoes, the PSD levels were attenuated at 3.5 Hz, and were reduced at other frequencies. The highest PSD levels were found at the rear of the trailer, with resonance in the loaded boxes occurring at some frequencies. Horizontal acceleration was much less than the vertical acceleration. Understanding acceleration levels and frequencies that occur during shipment of perishables in refrigerated trailers will help to determine methods that will dampen the vibration energy and reduce the present losses in produce quality. , 1974 , 1981 Ceponis and Cappellini, 1985) . "The basis for management of quality is the prediction of damage resulting from the susceptibility of the produce to the hazards of distribution" (Schoorl and Holt, 1982). O'Brien et al. (1963) also stated that, "Two factors affect the bruising of fruits: the magnitude of the force and number of times this force is repeated at a given location." It has been suggested, however, that vibration may cause more bruising than impacts (Goff and Twede, 1979). Apple bruising was influenced by the quality of the road, shipment distance, and the type of container in which they were packed (Schulte-Pason et al., 1989). Reducing vibration and rubbing of peaches during transport from the orchard to the packinghouse reduced surface discoloration (Phillips, 1988) . Laboratory tests have shown that table grapes positioned on the top layer of a stack sustained more damage than when they were in the bottom layer. The damage was a result of acceleration levels in the top layer being twice that of the lower ones (Fischer et al., 1989) . F resh fruits and vegetables are subjected to injuries during handling, transportation, and distribution. Cherries, tomatoes, nectarines, and Bartlett pears have demonstrated these losses, ranging from 15 to 68% of their total market losses (Ceponis and Butterfield
doi:10.13031/2013.28431 fatcat:qpn5mpflmfgc7m6atf5z4ulhvq