Causes of fruit bruising on transport trucks

A study of the cause of fruit bruising on transport trucks showed that the damage occurs in the top layers of fruit in containers. The amount of bruising has a direct relation to the magnitude of vibration accelerations in the top levels of fruit. These accelerations, generated at the road surface, are transmitted to the fruit through the truck chassis, suspension system, and bed. The effectiveness of the suspension system determines the extent to which vibration accelerations are minimized before reaching the fruit. Accelerations may be as much as four times as great in the top layers as in the bottom layers of fruit. The characteristics of the fruit species and its position in the system determine the acceleration to which it is subjected. Susceptibility to transport bruising varies with type of fruit and variety. In respective order of susceptibility to transport bruising, fruits are (1) cling peaches, (2) round tomatoes, (3) pear-shaped tomatoes, (4) apricots, and (5) pears. Depth-of-bin studies showed an optimum depth of 24 inches; this is related to accelerations in the top layers of fruit and the per cent of total fruit in the bin that is free to move.