The US Food & Drug Administration recently gave the green light to ozone treatment for all foods. An important food safety weapon – yet one surrounded by controversy. Pam Ahlberg reports on ozone’s rise to acceptance by the FDA and examines some of its new applications as ozone goes mainstream.

A powerful and environmentally friendly weapon in the war against food-borne pathogens was made available to US food processors in June when the US Food and Drug Administration (FDA) approved the use of ozone – as a gas or dissolved in water – in the processing of all foods, including meat and poultry.

Ozone has been used in water treatment for nine decades and has been approved in the US as Generally Recognized as Safe (GRAS) for treatment of bottled water since 1982. In 1975 the FDA accepted the use of gaseous ozone up to 0.1 ppm in meat-aging coolers. In June 1997 an independent panel, convened by the Electric Power Research Institute (EPRI), granted GRAS status for ozone use in food processing, allowing ozone use in washing, handling and packaging processes. This latest FDA ruling approves ozone as an additive, allowing it to come into direct contact with food.

Kansas State University professor and former American Meat Institute Foundation president Dr James Marsden said, “The FDA approval of ozone as an anti-microbial treatment provides the food industry with a safe and effective means of reducing contamination on meat and poultry, fruits and vegetables, and seafood.”

Ozone is formed by applying electrical energy to the oxygen molecule, which splits some portion of those oxygen molecules in half, into singlets of O. Those single O atoms attach to O2 for a very short time, becoming O3, which has a half-life in its natural state of about 20 minutes. During that active phase, ozone works as an oxidant to kill harmful microorganisms. Afterwards it converts back to oxygen by releasing its singlet of O. Because of its short half-life and unlike chlorine, ozone leaves no residual in food.

Food Safety Product Offerings

Even before ozone received GRAS status in 1997, a number of companies had begun working to develop food industry applications. Industrial gas company BOC Gases (Murray Hill, NJ), introduced its Macron™ Loop system with great fanfare back in 1998 at the International Poultry Show in Atlanta. The system offered poultry processors an ozone treatment to reduce bacteria in their chiller baths. The system moves chiller bath water, via a sanitary pump, to a mechanical filtration device called the Macron filter. The filtered water, which is injected with ozone gas to kill the bacteria, is then sent back to the chiller bath.

Days after this latest FDA additive approval, BOC announced an alliance with RGF Environmental Group (West Palm Beach, FL) to further market ozone-

“Demand is driven by environmental problems associated with chlorine, greater sensitivity to water usage, and consumer demand for safer and fresher foodstuffs”

based applications for treating food.

Dennis Smithyman, BOC’s vice president of Global Food Markets, says the FDA ruling will allow his company to introduce ozonated water directly onto carcasses during the washing and chilling processes to increase anti-microbial efficacy.

Praxair, Inc. (Burr Ridge, IL), another industrial gas company, is also developing food industry ozone applications. In 1999, the company, in an alliance with the water treatment company Zentox (Poquoson, VA), developed the Cascade water reuse system. Like the BOC system, Praxair’s Cascade system uses ozone to disinfect and recycle poultry wastewater.

These days Praxair is putting its energies into an ozone technology designed to disinfect fresh fruit and vegetables. According to the company, lettuce washed with ozonated water looks and tastes significantly fresher than the same product treated with chlorinated water and enjoys a 50% longer shelf life.

According to Dr Meg Barth, vice president of quality, research and development at Redi-Cut Foods, Inc. (which pilot tested the Praxair system in 2000), the system dramatically reduces water usage, has a greater efficacy in treating bacteria in water than other technologies and chemicals, and reduces discoloration on cut surfaces.

Cyclopss Corporation (Salt Lake City, UT) is also working to develop ozone applications for food. In March the company was issued a broad patent by the US Patent Office for the use of ozone combined with food-grade surfactants for use in all food processing activities. Cyclopss has in-plant test systems ready to install at poultry plants for use on processed carcasses. Additionally, with this final ruling, projects with fruit and produce growers, fresh salad packers, beef processors and fish packers that have been on hold for as long as 2 1/2 years are expected to be restarted.

Moving Forward

Until recently ozone technology was most practical in large industrial applications, such as water treatment and pulp bleaching. Before this latest FDA approval, food processors were reluctant to invest in a technology with such limited application. However, things should begin to change now as poultry, beef and fruit and vegetable processors begin to explore a much wider range of food safety uses for ozone. What will also drive demand are continued concerns about the environmental problems associated with chlorine, greater sensitivity to water usage, and consumer demand for safer and fresher foodstuffs. The next six months should prove promising for this important food safety weapon.

By Pam Ahlberg

Pam can be reached by email at:

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