Dow: Final 'kill step' for pathogens

With so much at risk, most food professionals recognize the importance of putting food safety first within their processing and packaging departments.

“Companies are expected to implement an effective food safety plan for their facilities with validated controls and measures in place to assure product and consumer safety​,” said Paul Hall, Ph.D., a food safety consultant and former president of the International Association for Food Protection.

“It’s a business imperative that companies avoid recalls and invest in new technologies to ensure their products and processing facilities are as free from pathogens as is practically possible​.” 

Improving food safety​

While the producers of food and beverages have already invested significantly in safety processes and technologies, disease outbreaks and product recalls still happen with depressing regularity.

In 2011, for example, there were a total of 5,648 foodborne outbreaks in the European Union, resulting in 69,553 human cases, 7,125 hospitalisations and 93 deaths, according to the most recent “European Union Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Foodborne Outbreaks,” published in April 2013 [1].

When you examine industry data on contaminations and recalls, you see a number of different pathogens are involved, with Salmonella​ causing the most hospitalizations. Yet, it’s the robust and resilient Listeria monocytogenes​ that often cause the most serious damage.

Of the 1,476 human cases of listeriosis reported in the EU during 2011, more than one in 10 proved to be fatal, with cheeses, fermented sausages and fishery products at particular risk for contamination, according to the Food Standards Agency (FSA). The disease is just as burdensome financially, costing the UK economy alone an estimated £245m a year, the FSA reports.

Listeria monocytogenes​ is such a challenge to control because unlike many bacteria, it can grow in cold environments such as the refrigerated rooms in processing plants, spiral freezers, and chilled food sections in supermarkets.

As consumers continue to turn to ready-to-eat foods such as pre-made salads, sandwiches, meat spreads, sushi and other foods that don’t need further cooking, there is the fear we are inadvertently providing Listeria​ monocytogenes​ with the perfect conditions in which to flourish, and without an additional “kill step” of cooking before the foods are consumed.

Combating contamination​

How can we eliminate Listeria​ monocytogenes​ and other pathogens before our foods make it onto the supermarket shelf?

A natural place to look for improvements would be within the facilities used to process and package our foods and drinks before they are distributed to market. This includes improving the cleanliness of processing staff and looking for ways to destroy dangerous microorganisms that may be hiding in unexpected and hard-to-reach places.   ​

Broadly speaking, conventional sanitizing techniques use heat, chemicals, ultraviolet (UV) light or radiation to destroy microorganisms. While effective, some may fall short when it comes to their use in food processing environments. For example, conventional chemical sanitizers must be manually wiped or sprayed onto surfaces, opening the door to human error. Also, there will always be areas that cleaning staff cannot reach, increasing the risk that microbial contamination will remain.

Recognizing the need for an additional step in sanitization of prepared-food manufacturing spaces to augment manual chemical cleaning and sanitization practices, Dow Microbial Control has launched an automated whole room sanitization system that leverages the power of ozone to swiftly kill bacteria on surfaces and in the air, and then dissipating without a trace.

The company’s Advanced Oxidation System (AOS) Certified technology penetrates hidden areas in equipment, drains, air conditioning vents and fabrics to free them from microbial contamination. The power of AOS Certified whole room sanitization has been proven successful in field trials with well-known brand owners as well as in recent studies by organizations such as Campden BRI, the UK’s largest independent group carrying out research and development for the food and drinks industry.

“The efficacy of ozone in a high-humidity environment has been demonstrated in both laboratory and field trials, for both food contact surface sanitization and the sanitization of the production environment, including areas that are hard to clean and disinfect​,” said Lawrence Staniforth, contracts manager within the Heat Resistance and Decontamination group at Campden BRI.

The organisation, which assesses technologies but does not endorse specific products, tested AOS at its laboratory facilities and found the system reduced the contaminating organisms dried onto stainless steel surfaces both in exposed and hard-to-reach places.

Sustainable technologies​

AOS certified technology uses ambient air to generate ozone, which is then combined with a non-condensing humid atmosphere to create a vapor that fills the room and penetrates every crack and corner. The sanitizer fully dissipates, leaving no moisture or residue, making it safe even for dry environments such as bakeries. It is designed with long-term sustainability in mind, reducing nuisance microbes with minimum impact on the surfaces and machinery of the processing area.

The antimicrobial powers of ozone — one of the most powerful antimicrobial agents available in the food industry — are well known throughout the world. It has been used for more than 100 years as a sanitizing agent in applications such as drinking water and wastewater treatment.Historically, the biggest downside of using ozone is the difficulty in distributing it evenly and reliably to the areas that need to be treated. However, when applied uniformly, it is extremely effective.

To overcome the challenge of even and consistent distribution, Dow Microbial Control worked closely with a team that includes top microbial control scientists and ex-NASA engineers to create a system that controls ozone dosing, room humidity and process time. AOS Certified technology precisely monitors the entire treatment cycle and Dow certifies the treatment every time it’s used. 

Given the health and financial risks associated with Listeria monocytogenes, E. coli, Salmonella​ spp. and other microbial contaminates, the need for careful sanitization in process plants is as important as ever. Fortunately, emerging technologies are providing new and innovative ways to combat these dangerous pathogens – protecting lives and livelihoods in the process.’

Tony Reed is business development manager for Food Safety within Dow Microbial Control’s New Technologies Business Development team. With 23 years of chemical industry experience, he holds a Master of Business Administration degree in Business Management from La Salle University (Pennsylvania) and a Bachelor of Science degree in Business Chemistry from Western Michigan University.​

References: ​The European Union Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks in 2011. EFSA Journal 2013; 11(4):3129 [250 pp.]. doi:10.2903/j.efsa.2013.31