Fresh Fruits & Vegetables
Much attention is being focused on the safety of fresh fruits and vegetables and the methods to reduce and eliminate human pathogens from this produce. Traditionally chlorine has been the most used sanitizing agent for washing fresh produce. A disadvantage is its limited effect in killing bacteria, mold and fungus. Chlorine has also been under increased review by environmental and health communities. Why Ozone over Chlorine?
Ozone as an oxidizing agent is 1.5 times stronger than chlorine and is effective over a much wider spectrum of microorganisms than chlorine and other disinfectants. Ozone kills a wide variety of bacteria such as Escherichia coli, Listeria, and numerous other harmful food pathogens much faster than chlorine and is free of chemical residues.
Fresh fruits and vegetables are washed first by ozonated water, and the wash water can be recaptured and treated by a combination of ozonation and filtration. The treated wash water is free of bacteria, color, and suspended solids and can be recycled to reduce water usage. Unlike conventional chlorine-based washing systems, wastewater discharged by an ozonation process is free of chemical residues, a growing concern related to the environment and groundwater pollution. Ozone can also destroy pesticides and chemical residues, such as chlorinated by-products (Landlais et al., m1991).
Gaseous ozone is a strong sanitation and fumigation agent and can be used to sanitize foods in the storage room and during shipping to percent bacteria, mold, and yeast on the food surface and to control insects. It can eliminate undesirable flavor produced by bacteria and chemically remove ethylene gas to slow down the ripening process, thus allowing extended distribution.
Areas suitable for ozone usage:
Process Water Sterilization
There are many situations in which process water is a contaminate to the produce itself. This water often causes cross-contaminated either before or during the processing cycle. Ozone added to this water kills the harmful micro-organisms that could contaminate the product. Ozone can also destroy chlorine byproducts, pesticides, and toxic organic compounds in the process water without leaving toxic residues on the produce.
Fruit and Vegetable Washing
The washing of vegetables and fruits using either an ozonated water spray or flume reduces microbial counts on the surface of produce. Ozone is particularly effective against E. coli, the food pathogen of most concern to the produce industry.
Fruit and Vegetable Storage
Ozone can be employed in produce cold storage to protect against mold and bacteria. As in the wine industry it can be used to not only destroy mold and bacteria in the air and on the surface of produce; but also deodorize the storage facility. Ozone has been shown to extend the shelf life of fruits and vegetables. Documentation has been made available on a wide variety of produce such as: apples, grapes, potatoes, lettuce, tomatoes and strawberries, broccoli, pears, cranberries, oranges, peaches, grapes, corn, and soybeans.
Process Water Recycling
Ozone is a perfect candidate for treatment of water for recycling, since it is a powerful oxidizing agent. This recycling of the water becomes a cost effective alternative to fresh water costs, waste water treatment and permitting restrictions.