Economic losses caused by post harvest diseases are an important problem in citrus plants. Most spoilage in oranges in storage and distribution is caused by penicillium digitatum. Currently this is controlled by the application of synthetic chemical fungicides. These compounds have environmental impact and their use may be reduced in the future by regulation.
Juice producing companies requires significant consumption of water and chemicals (detergents & disinfectants) for cleaning and disinfection of facilities, leading to a high volume of waste water.
AINIA technology center, Spain, has been investigating the development of cleaner post-harvest techniques applied to the citrus industry since 2010. This research has focused on three interrelated areas: hygiene equipment, product conservation and water treatment.
Laboratory and pilot work that has been completed concludes that the technical feasibility of developing systems for post-harvest treatment based on the use of ozone and ultraviolet light, is as effective as conventional systems,
and reduces the use of fungicides. Advanced oxidation of water discharged will regenerate the water that was used in treatments for possible reuse. Ozonated water used for cleaning juice tanks is as effective as the use of chemical disinfectants, but using a lower consumption of disinfectant and water.
Ozone is a powerful oxidant with a broad-spectrum bactericidal effect which does not generate chemical waste since it degrades rapidly to give oxygen, and ultraviolet light (UV) is a germicide that has no residual effect nor secondary.
Thus the use of advanced oxidation, has a high potential to become a useful tool for the citrus industry, mainly for its environmental benefits compared to traditional chemical fungicides used in post-harvest treatments or traditional disinfectants used in cleaning facilities.