Water Conditioning & Purification Magazine

Ozone and Food Processing: From Fresh Produce to Seafood, a Niche Market Grows

By Christopher Lee, CWS-V, and Ronald Rogers

Healthy food. Convenience food. Ready-to-eat food. Do you eat this food? When you eat ready to eat “fresh pack” food products, does food safety come to mind? Do you see dollar signs for your dealership? What do these questions have to do with a water treatment business? A great deal, if you’re looking for new markets.

With the advent of ready-to-eat fresh pack food products has come new risk and liability. In recent years, several outbreaks of food borne illness have grabbed the headlines. From juice to out-of-the-bag salads, illness outbreaks and lawsuits have caused producers of these products to re-think and change food-handling practices. Thus, new doors for water treatment are opening.

A new approach to clean
Fresh pack foods require cleaning and processing prior to packaging, yet they’re often delicate and fragile. Much of the processing is done manually and with water. Manual handling of products can expose them to bacterial contamination so sanitary conditions are imperative. The general objectives of wash water are to sanitize, retard spoilage and remove gross surface contaminants.1 Historically, chlorine has been used as a water disinfectant and contact sanitizer. However, both nutrition-conscious and natural foods advocates have objected to use of chlorine-based disinfectants in this water, often citing the risk of chlorine by-products and the potential risks associated with them. In addition to food use, extracts of raw products are used in pharmaceutical manufacturing. Some of these pharmaceutical processes prohibit use of chlorine as a sanitizer or disinfectant. An effective sanitizer without residuals or by-products of concern is what the industry has been waiting for to fill the gap.  

Ozonated water has been used in food processing in Europe for decades. Until recently, ozone and ozonated water were permitted for use as sanitizers for non-food contact applications only. All that changed in 1997 when a panel of experts affirmed the use of ozone as generally recognized as safe (GRAS) for use in food processing.2  With high oxidation potential and natural decomposition to diatomic oxygen (O2), ozone—or O3— presents an ideal agent for disinfection of potable water and water contact processes. Its reversion to oxygen leaves no residual and allows packagers to use labels such as “100% natural” while still ensuring product safety and quality. This ruling still didn’t specifically approve direct contact with food and the packager/producer must be responsible for testing to assure no negative impact to product to win approved use of O3.

New opportunities
Opportunities for ozone use in food processing can range from the obvious to the unexpected. For instance, Sprouters Northwest of Kent, Wash., a manufacturer of ready-to-eat seed sprout varieties, wrestled with a dilemma—how to ensure a safe product, while providing a natural food, a primary concern of the clients. Sprout manufacturers have had to eliminate potential contamination by E. coli and Salmonella in their products. Previously, seeds were rinsed with a solution of 20,000-to-22,000 parts per million (ppm) of chlorine—almost half of the strength of straight household bleach—prior to germination to sanitize the raw material. Extensive rinsing was required after sanitizing since residual chlorine adversely affects germination of seeds.

Handling of concentrated hypochlorite solutions also posed safety concerns in the plant. Additional chlorinated water was used in misting and washing the sprouts prior to packaging. Now, a reservoir of ozonated water has replaced chlorine. Bill Jones, owner of the sprout operation, reports, “Since the installation of the ozonator, the use of hypochlorites has been eliminated in routine processing operations.” Ozone has satisfactorily replaced chlorine while maintaining product safety and quality.

Cracking the shell
A more unusual application for ozone is the packaged oyster industry. These products are found in glass-enclosed grocery store cases nationwide. Oysters can have extremely high bacteria levels on the outside of the shell prior to packaging. They’re shucked by hand and then agitated by air in a water bath to clean them prior to packaging. At the Minterbrook Oyster Co. plant in Gig Harbor, Wash., the oyster washer air stream was ozonated as well as the rinse and packaging water. This process went online in late 1997; and, as a first in the industry, it was heavily scrutinized both by the Food and Drug Administration (FDA) and Washington State Department of Health. Erika Wiksten, general manager, reports a reduction in bacteria levels as well as higher quality product at the end of the “use by” date since the use of ozone began—i.e., longer shelf life. Further, Minterbrook’s product now complies with strict non-chlorine regulations imposed by pharmaceutical manufacturers. Ozonated wash down water has even replaced hypochlorite solutions. The same opportunities exist for other shellfish and seafood.

Other applications for ozone have been documented showing benefits of its use. Ozone is being employed in both aqueous solution and gaseous form to aid in food sanitizing, processing, storage and odor control.3 Some applications require water with little ozone residual due to workplace environment. Other applications may require highly concentrated solutions of ozone to achieve the desired results. And still others may involve strictly gaseous ozone dispersion for control of environmental conditions. Thus equipment applications can range from small UV ozone generators percolating in storage reservoirs to high production vacuum and pressure corona generators using oxygen feed. Some of these uses may be unfamiliar to the dealer; however, many manufacturers of ozone equipment provide excellent technical support for designing and sizing applications.  

Tapping into ozone
So, how can you tap into these opportunities? Get to know your local food processing industry, whether it’s fruits and/or vegetables that require washing for processing or seafood handling at markets or restaurants. Learn not just what products are being produced, but how and for what purposes. Pay attention to the media. The origin of new ozone prospects may jump out at you in business pages or headlines. Due to the highly perishable nature of many fresh pack products, small local producers often thrive by providing produce to high-end produce markets and restaurants. Specific targets are organic and natural producers of foods, nutritional and health products and producers of uncooked/non-pasteurized food products.

When looking at an application keep in mind some guidelines. In the United States, ozone use is relatively new in food processing. Your prospect may require a lot of education prior to accepting it as a viable process. However, many applications of successful use in food processing have been documented. Consult the International Ozone Association—(203) 348-3542 or www.int-ozone-assoc.org—for specific applications. Take advantage of strides already made in the use of ozone. Providing documentation of a successful ozone application can go a long way in establishing client confidence in the technique.

Remember also that ozone applications, equipment and operation can be quite different and more complex than other treatment techniques now commonplace in the industry. If you’re new to ozone, do your homework. Research it. Read the trade publications. Take appropriate study courses and certifications at the Water Quality Association. Develop a good relationship with your supplier. Consult more than one source for technical support.

Return on investment
With all businesses, return on investment must be considered. Returns are sometimes directly measurable, such as cost savings. Other returns may be less tangible like providing new markets and advertising approaches for your client or providing greater safeguards for their products. Prevention of food borne illness is a primary concern. Enhancements to processing methods are often regarded as inexpensive insurance policies.

Since your client may view use of ozone as experimental, consider proposing either a pilot/bench test or a base design to prove effectiveness before implementing major changes to an operation. This may likely be required anyway. Designs that cause the least impact to existing operations are more favorable. Regulatory approvals may still be required prior to using ozone. The FDA, U.S. Department of Agriculture (USDA) and local health departments may want to review changes to existing procedures prior to implementation. Use of ozone can be marketed by focusing on its benefits: improved quality and safety, extended shelf life and the potential for providing new markets for your customers.  

Conclusion
The trend in food retailing has been toward offering more ready-to-eat products. In-store/take-out food service is now the norm nationwide. This trend is reflected in produce sections of supermarkets as well. As the market for fresh pack products expands, so will the need for safe, acceptable methods of sanitizing and disinfecting water and food products. The techniques for delivering ozone to water and air are well established. The opportunities for using these techniques are growing. Make sure you’re prepared to take advantage of them.

References

  1. “Introduction to the Use of Ozone in Food Processing Applications,” International Ozone News, Vol. 26/No. 5, 1998.
  2. Electric Power Research Institute, News Release, May 1997.
  3. “Use of Ozone in Food Processing,” Food Technology, Vol. 51/No. 6, June 1997.

About the authors
Christopher Lee is a water quality chemist with Pacific Rim Water Products Inc., Sumner, Wash., an original equipment manufacturer and provider of water treatment services and equipment. He holds a bachelor’s degree in chemistry from Bridgewater State College, Bridgewater, Mass., and has worked in the environmental and water quality industries for more than 13 years. Lee is a member of the Water Quality Association’s Science Advisory Committee and has earned the WQA’s Certified Water Specialist-Level 5 designation.

Ronald Rogers is a senior sales engineer with Pacific Rim Water Products Inc. Rogers holds a bachelor’s degree in chemistry from California State University and has worked in the water treatment industry for 30 years. He’s member of the WQA Ozone Review Committee.

Both can be reached at (253) 863-2188, (253) 863-3408 (fax) or email: pacrim@frugal.com

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