Spain: ozone and ultraviolet combination reduces citrus chemical use

Economic losses caused by post harvest diseases are an important problem in
citrus plants. The vast majority of rotting oranges and mandarins present throughout the Marketing process are mainly due to Penicillium digitatum and Penicillium italicum, respectively, causing green and blue rot. Currently its control, is based primarily on the application of synthetic chemical fungicides
that cause environmental impact and also some European officials claim a reduction in their use.

On the other hand, in the juice producing companies, the processes of cleaning and disinfection of facilities requires significant consumption of water and chemicals (detergents, acids, alkalis, disinfectants), leading to a high volume of wastewater.

AINIA technology centre, along with companies in the citrus industry (Fontestad, SAT Cítricos Valencianos and Agriconsa) and specialized equipment (UV Consulting Peschl 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.

Results.

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. Also, the advanced oxidation of water discharged will regenerate the water that was used in treatments for possible reuse.

Also, it was found that the use of ozonated water for cleaning juice tanks is as effective as the use of chemical disinfectants, but using a lower consumption of disinfectant and water.

According to Albert Canut, technician of the Quality and Environmental Department of ainia technological centre, "The technology that has been developed, will help in the near future to: reduce the presence of pesticides in final products and in waste-waters, reduce the cost for non-use of chemicals, conserve water and reduce waste management, all of this without losing trade quality of the final product and reducing environmental impact."

Advantages of using advanced oxidation.

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, according to econoticias.