The Natural Power of Ozone

Another example of ozone’s cleaning ability was proven effective on a very soiled floor drain. After an ozone system was installed in the plant, a very low flow line serving a dissolved ozone sensor was secured with zip ties to an existing drain line. Several months later, the area of the drain receiving the small ozone stream was visibly clean.

The first example shows the ability of ozone to keep a surface clean. The second shows ozone’s ability to clean a dirty surface. Ozone is most effective if used continually. This stems from the fact that at 2 to 3 ppm it can easily be overwhelmed by heavy biological oxygen demand (BOD) loads. Low flow of continuous ozone sprays or low ambient levels of gaseous ozone are the most effective way to maintain clean surfaces and prevent biofilm formation. The ozone sprays are started minutes before production to coat the surfaces with ozonated water keeping them sanitized during the production day. This preemptive approach to cleaning virtually eliminates biofilm formation and, when coupled with interventional cleaning, can lengthen the interval for full plant sanitation.

When properly applied the addition of an ozone continuous cleaning program will enhance plant sanitation. It is not a replacement for an existing good sanitation program but rather a complement to that program. In the process, it can reduce sanitation costs in both labor time and chemicals.

This side-by-side image of ozone versus no ozone in peach processing shows how when ozone is applied, hoses, belts, and other equipment stay cleaner—reducing the down time for sanitation.

Ozone in Seafood Processing

I mentioned earlier that many of the benefits of using ozone are industry specific. These benefits are not just theoretical but can be very quantifiable. Looking at a specific industry such as seafood, we find extensive adoption of ozone technology. Whole fish are initially sprayed with ozonated water on arrival at the plant. After the fish are headed and gutted, the insides of the fish are sprayed with ozonated water as are the knives, conveyors, deboners, fillet machines, and other direct contact surfaces. As the fish travel down the processing line, they pass under spray bars which provide an additional application of aqueous ozone. Augmenting that protocol is the interventional use of ozone on indirect surfaces during break times and shift changes.

What does this accomplish? For starters, it has been shown to lengthen shelf life and improve product safety. It should be noted that the degree of shelf life extension is dependent on the point of initiation of ozone processing. Processors will typically see a two to four day extension while distributors may see a one to two day extension. The result of this is that customer charge backs, a significant cost to seafood distributors, are dramatically reduced—producing significant additions to the bottom line.

Aquaculture operations also benefit from ozone. Onshore facilities use ozone to improve colloid flocculation, nitrite oxidation as well as to put more oxygen (the ozone by-product) into the water. In clear water aquaculture, the goal is to achieve a 95 percent reduction of pathogenic waterborne bacteria in water treatment systems. These benefits all contribute to better survival and faster growth. Hatchery operations are similarly enhanced with the use of ozone.

Ozone’s Role in Food Safety

From a food safety prospective, pathogenic bacteria get and deserve the biggest headlines. All bacteria are inactivated by ozone. But remember, ozone is a topical agent and is only lethal to what it can see. Most of the organisms we are concerned about are aerobic and therefore on exterior surfaces. But one bad actor is not—Listeria monocytogenes is a facultative anaerobe and it grows well in cooler environments as well as internally in protein products. The continuous cleaning capability of ozone provides the best defense against this serious food safety problem. Ready-to-eat (RTE) products are particularly susceptible to Listeria contamination and ozone’s unique organoleptic property of leaving no residue has made it become a effective agent in many areas of RTE sanitation.