Have a question?

Processor Issues :: Effect of Mechanical Harvesting
Systems on Fruit Microflora


For Florida to effectively compete in the world citrus industry, significant reductions in harvesting costs will be necessary. Mechanical harvesting (MH) can be thought of a two-step process: (i) removal of fruit from the tree and (ii) collection of fruit (immediately, by a catch-frame device or during retrieval of fruit from the ground). This study evaluates the microbiological aspects of mechanically-handled fruit with respect to fruit surface microflora and corresponding fruit juice microflora. Also, due to processor concerns with regards to the amount of sand present in mechanically harvested samples, experiments were undertaken to quantify the influence of mechanically harvesting on sand levels.


  • Evaluate the microbiology of the surface and juice of citrus fruit collected by the OXBO pick up systems.
  • Evaluate the amount of sand present on the surface of citrus fruit collected by the OXBO pick up system.

Key Findings (Updated on 10/07)

  • Control (hand picked) fruit had fewer microbes on the surface when compared to MH and MH fruit picked up with the OXBO pickup system (MH/PU), however no real trends can be attributed to harvest method for total fruit surface microbial loads for all runs. This result suggests that dropping fruit to the ground and/pr picking it up mechanically does not necessarily result in higher microbial loads.
  • Generic Escherichia coli was detected in four of the 20 pooled MH samples and in three of the 20MH/PU pooled samples, and Salmonella was detected in one of the 20 pooled MH/PU fruit, however there is no correlation between the presence of E .coli and Salmonella.
  • In all cases, juice samples contained significantly less bacteria than the corresponding fruit, often times being at or below the limit of detection. No generic E. coli or Salmonella were detected in the juice.
  • Fruit surface sand levels are significantly higher for MH/PU and MH oranges than for control fruit.

Activities Planned for 2007-2008

  • We plan to continue to evaluate the surface microflora of MH and MH/PU oranges for a 4th season and to evaluate the juice microflora of the corresponding oranges for a second season.
  • We will also continue to evaluate sand levels on MH oranges.

Publications and Extension Products


  • Annual progress report 2006-2007 - This work has been presented at the Florida State Horticultural Society’s annual meeting June 4th, 2007 in Palm Beach Gardens Fl, and will be published in the Proceedings of that meeting.

More information


Michelle Danyluk
Reza Ehsani

Visits since 05/21/2014