It is no secret that the food industry has been struggling with Listeria outbreaks in the past few years. In this blog post, we will discuss how ozone generators can be used in food processing plants to reduce the amount of listeria bacteria. With more and more people becoming conscious of what they are eating, it is important for processors to find ways to reduce potential contaminants in their products. Ozone generators have proven to be an effective way to do just that. Keep reading for more information!

Listeria Reduction with Ozone

The term “listeriosis” refers to a particular strain of seven different bacterial species. Listeriosis is an serious illness caused by the specific type of Listeria known as L. monocytogenes. Listeriosis is an infection caused by ingesting contaminated food. This illness is extremely hazardous for people with debilitated immune systems or those who are immunocompromised, and it has the potential to be deadly in some cases. Listeria disease and L. monocytogenes are two names for the same condition.

Listeria can grow in soil and is especially common in lettuce, cantaloupes, pears, grapes, artichokes, and other hardy vegetables. Listeria may also be present in all forms of meat. Raw meats, unpasteurized milk, raw veggies, and some ready-to-eat foods are all high-risk items for containing Listeria.

Since 2001, the use of ozone on foods has grown dramatically, with it being GRAS approved for direct application to food. Ozone has been shown to assist in the reduction or elimination of any monocytogenes strains present in food items.

The correct application of ozone is critical for it to work effectively against any germs. With most application procedures, there are a few fundamentals that remain the same.

Implementation of Ozone

Aqueous Ozone


The most frequent technique of utilizing ozone to destroy germs is to combine it with water and allow it to dissolve. Ozone is mixed with water using an ozonation system, then sprayed on the surface that need disinfection. Hard equipment surfaces or the exterior of a foodstuff may be treated in this manner.

There are several ways to spray dissolved ozone onto food and produce, one of the most effective being spray bars coupled with conveyers for ample contact time and full coverage. For disinfection, it’s critical that every part of the food or produce is exposed to the aqueous ozone.

Conveyer speeds, spray tip designs, and the amount of aqueous ozone all have an impact on how long the fruit or food is in contact with the nozzle. If there’s already a process for washing produce or food with water, adding ozone to it is very simple. This ensures that no steps are interrupted while simultaneously boosting disinfection.

Gaseous Ozone

Gaseous ozone is also utilized to eliminate pathogens from food and produce, however it is less prevalent than aqueous. The effects of gaseous ozone on bacteria have received less study. If gaseous ozone is going to be effective, it must take into account a variety of factors.

The quality of the water, as well as parameters such as temperature and humidity, all influence whether or not the process will be successful. There’s been research that suggests gaseous ozone may weaken L. monocytogenes bacteria strain; however, further study is necessary to determine efficacy based on all of the numerous variables.

All places where food, cargo containers, chambers, or rooms are all potential locations for disinfection. Any space that is properly sealed and able to hold the produce as well as ozone gas while maintaining employee safety is suitable. Air flow is critical in order to fully cover each angle of the produce. This procedure employs ozone levels of 1.0 – 100 ppm with contact times ranging from 20 minutes to 10 hours.

Bottom Line

As we have seen, ozone generators are an effective tool in the fight against Listeria. By implementing ozone generators into your food processing plants, you can greatly reduce the amount of Listeria present in your product.

With continued use of ozone generators, you can maintain a safe and healthy product line for your customers. If you are interested in learning more about how ozone generators can benefit your business, please contact us today. We would be happy to discuss this technology with you and answer any questions you may have.