Impact collisions during handling and their effect on internal bruising and surface splitting of 'Tempest' tomatoes (Lycopersicon esculentum).

An instrumented sphere was passed with tomatoes (Lycopersicon esculentum) through sorting, grading, and packing operations in 15 commercial facilities in Queensland, north-east Australia. The sphere is a tomato-sized, electronic device that contains an accelerometer for measuring the size of impacts in gravitational force, "g". It proved to be well suited to studies of tomato handling lines where impacts were found to mainly occur at transition zones between different mechanical components. Nearly 50% of large impacts greater than 160g occurred as the instrumented sphere moved onto ramps. The most direct route for first class fruit between bin-tip and carton entailed passage through an average of 25 sites that generated impacts averaging 91g, but the majority of these were unlikely to cause serious injury to the variety 'Tempest'. Laboratory tests using a pendulum impact-rig correlated incidence of injury to drop-heights and impact acceleration, and 'Tempest' was found to tolerate impacts that would generally be considered extreme for fresh produce in most handling situations. For mature-green fruit, severity of internal bruising generally increased with increasing drop-height, and drops above 60 cm onto steel caused injury that was considered commercially important. Coloured fruit (with more than 75% of the surface showing pink-to-red) were less prone to internal bruising and surface splitting than mature-green fruit. Fruit size had no effect on severity of internal bruise development but larger fruit were more likely to split than smaller fruit following large drops onto a steel surface. Based on these results it seems that packing-line managers could operate equipment more quickly when handling coloured fruit compared with mature-green. [ABSTRACT FROM AUTHOR]