Produce Washing with Ozone Water

Various type of produce are washed with ozonated water including fruits, vegetables and potatoes. In some cases, the use of ozone water treatment is the first time a disinfecting agent has been applied to the produce during the washing or conveying process. In other cases, ozone has been added to or replaced an existing disinfecting agent such as chlorine or peracetic acid.

Ozone is a widely used disinfecting agent that has bene used for over 120 years to treat drinking water. More recently it has been applied to a wide range of applications for disinfection including bottled water, cooling water systems, rain water harvesting, as well as in the produce industry. Research has shown that in some cases the shelf life of the produce can be extended by using ozone. In other cases it is added to insure food safety.

Potatoes is one area where the use of ozone is being explored. A difficulty with potatoes is that they carry a large amount of dirt from the field to the processing facility increasing the potential for bacteria to enter the system. Normally multiple washes are required to get the potatoes to the stage where they can be processed.

This fall, O.C. Schulz & Sons, Inc., a potato grower-packer-shipper located in North Dakota installed an ozone system on a wash line as a contribution toward food safety. They are hoping that the ozone will also extend shelf life for the potatoes.

Processors of potatoes, such as potato chip manufacturers, often use a disinfecting agent in the conveying flumes that are used to move the potatoes from the trucks to the fryers. While the high temperature in frying is likely to kill any pathogens on the potatoes, food producers today are looking to decrease the odds that some pathogen can get through their systems. Thus they are adding multiple barriers to prevent organism from getting to consumers.

In a test at a potato chip processing factory, Spartan found that ozone could provide the same benefit as peracetic acid while substantially lowering chemical costs. So one option is substitution of ozone for other agents, but in other cases processors may add ozone without removing the existing disinfectant agent to increase the potential for a total kill.