Food Safety

Food Safety’s Smallest Challenge: Microbes

Hot Mama’s was on a strong growth trajectory for its private label humus, salsa and dips. Then an invisible enemy shut her down.

By Kevin T. Higgins, Managing Editor

In the never-ending struggle to keep food safe and microbes at bay, the operation sometimes is a success but the patient dies. Such was the case with Hot Mama’s Foods.

Hot Mama’s had tapped into a bull market for its private label hummus, salsa and dips. In 2013, the two-plant processor racked up sales of $33.3 million, a 15 percent increase from the previous year. Four-fifths of sales were to Trader Joe’s and Target, which marketed the products under its Archer Farms name.

Demand was so strong that Hot Mama’s outgrew its Elk Grove Village, Ill., plant and leased 68,000 sq. ft. in nearby Wheeling, Ill., another Chicago suburb, in a facility that formerly housed an Orval Kent Food Co. commissary. A few months later, disaster struck in the form of a May 2014 recall involving Listeria monocytogenes, quickly followed by a second Listeria recall when a test-and-hold procedure was violated.

Hot Mama’s suspended operations while CBRE Chicago, a real estate management firm, brought in James Marsden, a professor of food safety and security at Kansas State University, to address the contamination issue. In a white paper published by the college's Food Science Institute, Marsden notes that, although “the plant and equipment had been cleaned and sanitized using pre-existing protocols and chemicals,” swab tests were positive for Listeria on two pieces of equipment and in a drain.

In cooperation with FDA, Marsden developed a remediation plan involving ozone gas and silver dihydrogen citrate (SDC), a disinfectant and food contact-surface sanitizer approved by the EPA a few years ago.

An extremely powerful oxidizer, ozone was first used in the early 20th Century for wastewater treatment, but it was not until 2001 that FDA cleared its use in food contact. Several makers of ozone generators, many with roots in pool water sanitization, have targeted the food industry since, with limited success. If the concentration of ozone in an aqueous state is too high, degradation of seals and gaskets and even pitting of stainless steel can occur. Worker health concerns due to outgassing and ozone’s instability also have limited the technology’s adoption.

Gas-phase ozone was used to treat the plant’s air-handling equipment, followed by surface disinfection with SDC. Ozone gas also was used to decontaminate all non-food processing areas, while SDC was the remediation for the processing and packaging areas, lift trucks and other equipment.

A second microbiological mapping study was conducted to assure the contamination “was fully addressed,” Marsden wrote, and a preventative maintenance and sanitation schedule including semi-annual mapping studies was submitted to FDA and the building’s owner. Based on 300 environmental samples, he declared pathogen eradication had been successful, and “FDA issued two letters to the owners of the facility, releasing the equipment and facility for manufacturing of FDA-regulated product.”

Unfortunately for Hot Mama’s, the clean bill of health came too late. The entire Wheeling staff was laid off last July, and the company’s Massachusetts plant was subsequently sold to another food processor.

Hi-ho, silver

Marsden’s paper explicitly cites the vendors of both the ozone generators and the SDC-based cleaner, sanitizer and spraying and foaming equipment.

Pure Bioscience Inc. is an El Cajon, Calif., developer of the SDC technology. After developing the stabilized silver-ion complex in 2001, the firm spent the next decade seeking EPA approval for use as a hard-surface disinfectant in food plants. Since gaining EPA registration, the firm has secured GRAS designation and is seeking FDA approval for direct contact with food. “Soaker pads for poultry would be a very good application,” suggests CEO Hank Lambert.

Like ozone, antimicrobials with a silver ion base have struggled to gain food-industry acceptance. Silver ion has been used as a coating on drain traps and as an additive in epoxy and other flooring systems, with limited acceptance. Several manufacturers and installers of floors have offered it as an option, and UK-based Flowcrete has incorporated it as a standard feature. But many food processors dismiss silver ion as an added cost that doesn’t negate the need for regular cleaning and sanitizing and the removal of biofilm formation.

Medical device manufacturers embrace the technology, Lambert points out, but Pure Bioscience was on the brink of bankruptcy two years ago because management pursued multiple applications. He was part of a new board and executive management group that “strictly focused on building SDC as a food-safety solution.” It is effective in destroying bacteria, fungi and viruses, the last a microbial contaminant of rising FDA concern.

It also is the least toxic sanitizer available and has a higher efficacy than conventional sanitizers such as chlorine and quaternary ammonia. “Basically, it’s a green product, and we’ve consistently been able to show 90 percent-plus higher reduction in bacteria on surfaces,” adds Lambert. Faster kill (typically 30 seconds) and 24-hour residual protection also help justify a higher cost that he characterizes as “pennies a month.”

Water jolts and joules

Corona discharge and electrolytic generators typically are used to produce ozone. Jimmy Larsen, CEO of Jimco A/S in Rudkoebing, Denmark, instead uses short-wave ultraviolet tubes to split oxygen molecules and recombine some in groups of three before blowing the ozone into the air. His system received an EU environmental award and is more benign than hypochloride or peroxide, which can result in the inhalation of cancerous chloric acid, he says.

At 0.05 ppm, ozone can safely be inhaled by humans. A Polish slaughterhouse operates Larsen’s Flo-D fixed system throughout the workday during hog butchering. More typically, the 330-volt system is turned on remotely from a sealed area and runs for two hours to produce a “nearly sterilized” environment, he says. Because the system sucks out much of the available oxygen in the air, it is equipped with sensors to immediately shut down the unit if someone enters the room while it’s in operation.

The UV lamps consume 3 kW of electricity to disinfect a 53,000-cu.-ft. area, he calculates, less than the energy needed for a hot water washdown involving chemicals. Because the set point of ozone parts per million is tightly controlled, corrosion that can occur with chemicals is avoided, and the plant can return to production more quickly because surface drying isn’t involved.

Molecular reorganization is the basis not only of ozone generation but also electrolyzed water, a technology with roots in Japanese carpet cleaning. By injecting electricity and salt into water, separate streams of sodium hydroxide and hypochlorous acid are created. At a pH of about 11, the sodium hydroxide is a very effective cleaner, according to Larry Smith, president of GoGreen Electrolyzer Corp., Port Orange, Fla.

Unlike quat, chlorine and other conventional sanitizers, hypochlorous acid kills most microbes in 10-15 seconds. Chemical sanitizers usually require 10 minutes, he notes, and food sanitation crews typically don’t wait 10 minutes before rinsing contact surfaces after disinfecting them.

“There’s nothing better than ozone in killing bacteria, but you can’t put it in a bucket” for later use, Smith says, because ozone only has a 20-minute half life. Until someone finds a way to stabilize ozonated water, he recommends electrolyzed water.

The environmental and human health dangers from chemicals concern Smith, who points out only a fraction of commercial chemicals have undergone toxicity analysis. But eliminating chemical costs results in a fast ROI from electrolyzers, a key reason his former company was acquired six years ago by a major supplier of food sanitation chemicals. After purchasing the firm, the chemical supplier stopped selling and servicing the generators, according to Smith, adding, “I’ve never installed a system that had a payback of more than 12 months.”

Chlorine dioxide is another decontaminant and sterilizer that gradually is winning food & beverage converts. Derided as the “green cloud of death” by some, it more typically is applied in the medical field, though suppliers are beginning to target this industry.

“It’s the whole FSMA thing,” shrugs Paul Lorcheim, co-owner of CD ClorDiSys in Lebanon, N.J. Facilities trying to decontaminate after serious flooding used to constitute the bulk of food applications, but spiral freezers and other enclosed equipment are a growing share of his firm’s commissions.

Chlorine dioxide usually is delivered in an aqueous state, and Lorcheim claims to be the only supplier of gaseous ClO2. That eliminates the need for a transfer tank and adds pipe sterilization as a possibility. Orange juice processors who had used the iodine solution Iodafor to sanitize million-gallon storage tanks have converted to chlorine dioxide, eliminating the need to exhaust those tanks after cleaning.

Minimizing the presence of microbes in a food production environment should be a top priority of brand owners, contract manufactures and private-label suppliers, as Hot Mama’s dramatizes. For food managers attuned to the risks, there is a growing list of antimicrobials to consider.