Gaseous ozone has been shown to effectively combat mold and bacteria on various fruits and vegetables in cold storage. The main benefit of using gaseous ozone is that mold and bacteria are controlled both in the air and on the surface of the product. The end result to the produce grower/packer is a reduction of product spoilage. Additionally, gaseous ozone oxidizes and destroys ethylene gas that is released when fruits and vegetables begin to ripen by the following reaction:

Thus, the use of gaseous ozone can reduce ripening while in storage.

DEL Ozone has researched, tested, and collected data on the effects of ozone on a range of fruits and vegetables in cold storage.

“Continuous ozone exposure at 0.3 ppm inhibited aerial mycelial growth and sporulation on ‘Elegant Lady’ peaches wound inoculated with Monilinia fructicola, Botrytis cinerea, Mucor piriformis, or Penicillium expansum and stored for 4 weeks at 5C and 90% humidity. Gray mold nesting among ‘Thompson Seedless’ table grapes was completely inhibited under 0.3 ppm ozone when the fruit was stored for 7 weeks at 5C.”

“The number of colony forming units (cfu) of fungi, yeasts and bacteria naturally present on the berry [grape] surface was considerably reduced by a 20 minute exposure to ozone. Ozone treatments significantly reduced the extent of berry decay caused by fungi following cold storage and increased shelf-life.”

April, 2000 - As shown in the picture above, ozone at low concentrations greatly reduces the sporulation of green and blue mold. Ozone treatment lasted for 30 days at 3C and 95%RH.

The conclusions of the study were:

• 0.3 ppm O3 for 12 hrs. per day = spore control

• 0.8 ppm O3 for 12 hrs. per day = spore mortality

As a pesticide, ozone equipment must be registered by the EPA under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). DEL Ozone is an EPA registered establishment (EPA Estab. No. 071472-CA-001).

FDA/CFSAN - June 26, 2001 - Final Rule published in Federal Register (21 CFR Part 173, Docket No. 00F-1482) – “The FDA amends the food additive regulations to provide for the safe use of ozone in gaseous and aqueous phase as an anti-microbial agent on food, including meat and poultry.”