Water snobbery may be coming to the supermarket produce department.
Just as thirsty consumers are shunning tap water for purer, healthier bottled versions, some supermarkets are starting to re-evaluate the quality of the water they use to mist the "wet" vegetable area of the produce rack.
While Perrier won't be coursing through produce department misting systems, water that's been specially treated to head off microbiological contamination and even enhance overall product quality may well be on track to become part of the supermarket quality and safety enhancement arsenal.
For example, "two prominent nationwide grocery store chains" will soon be participating in a program to test the efficacy of electrolyzed oxidative water technology in produce department misting systems, according to the marketer of the system, Electric Aquagenics Unlimited.
Lindon, Utah-based EAU, working with a leading supplier of misting systems, KES Science and Technology, Atlanta, will be testing the chemical-free technology it claims will kill pathogens on produce and extend produce shelf life by up to a week -- things ordinary potable water won't do. Neither EAU or KES would reveal the names or locations of the supermarkets involved in the test.
Such a capability may sound attractive, but at least one retail produce executive looks askance at the concept. Bruce Peterson, senior vice president/general merchandise manager for perishables for Wal-Mart Stores, Bentonville, Ark., said a technology that purports to offer an added value by "treating" products actually runs counter to the true function of misting systems.
"Misting systems aren't employed to actually spray water on the product itself, but rather to condition the air in the produce case and provide for a more humid environment and slow down the moisture loss of some vegetables," Peterson said.
Properly configured, misting systems should provide just enough moisture to result in the top layer of vegetables such as leaf lettuces, broccoli and radishes staying slightly wet on the rack. Systems that coat vegetables with treated water would be a radical departure from the traditional misting procedure, Peterson said. In fact, produce cleansing and disinfecting initiatives, most notably those marketed to consumers in a take-home spray form, have largely been a bust, he added.
Still, as food safety concerns have mounted in recent years, supermarkets and misting system suppliers have been working to make sure misting isn't a weak link in the food safety chain. On top of properly calibrating systems to reduce the chance of product sitting in water on the shelf, some retailers have taken small steps to use cleaner water and deploy delivery systems that minimize the chance that bacteria can collect on the equipment and be transferred to the produce.
Some stores in the Milwaukee-based Roundy's chain employ a misting system that uses water that's been filtered through a device that ties into the stores' potable water system. Additionally, quarterly maintenance is performed on the system's water delivery lines and the filtration elements are cleaned or replaced, said Steve Jarzombek, vice president of produce operations. One of the most important efforts, though, has been to pay closer attention to the volume of water sprayed in the display case.
"Too much water is detrimental to the produce," he said. "I want it to have some moisture to rejuvenate the product after it's placed on the shelf, but not to where it's soaked. A system that's not timed correctly can end up drowning the produce."
In addition to tinkering with the system's timing and coming up with an optimal "two seconds on/four minutes off" schedule, the chain also has sought out newer-generation systems that are easier to control and maintain, and which use interchangeable spray heads that don't have to be adjusted with screwdrivers to change a spray pattern.
Systems suppliers like Corrigan Corp. of America, Gurnee, Ill., have worked to design products using materials that resist bacteria and waterborne mineral buildup. Company President Mike Corrigan said metal is giving way to plastics in spray nozzles as a way of reducing the buildup of mineral scale, which can leave a film on produce cases. Corrigan misting systems also can come with a unit that filters out sediment using reverse osmosis, a technology that uses carbon filtration and membrane separation components to trap and dissolve impurities.
Despite the growing interest in assessing the quality of the water used in misting systems, Corrigan pointed out the vast majority of supermarkets still use water that comes directly from the city water mains. And, with the exception of one case of Legionnaires' disease being traced to misted vegetables, the practice of widespread misting has served supermarkets safely over the course of two decades.
"There have not been any detailed studies that I'm aware of that have even looked at whether regular tap water is worse than treated water," he said. "We've looked at mold, mildew and bacteria counts in misted produce, but there's been no real determination of whether misting really impacts that."
Regardless, misting might well pose a fresh dilemma for some supermarkets. With the recent implementation of an organic labeling law that establishes national organic standards, grocers who want to be in strict compliance may have to watch how they merchandise organic produce that must be misted.
Documents outlining the national standards, prepared by groups like the California Department of Food and Agriculture and the Organic Trade Alliance, note that retailers should avoid merchandising conventionally grown vegetables that require misting directly above their certified organic counterparts. The reason: Water that collects on the conventionally grown product will drip onto the organic product, jeopardizing its organic status.
According to the CDFA document: "Automatic misting systems in particular may cause residues from conventional produce to migrate onto organic items. Organic items should not be stored below conventional product where water can run off."
Such a scenario amounts to a further argument for retailers segregating organic displays from conventional, something Wal-Mart and Roundy's, for example, have done in the wake of the new organic standards.
For all the attention misting protocol may be getting from a food safety standpoint, it doesn't appear to be particularly high on the list of retailer concerns. A more pressing issue may be one of functionality, specifically how to design systems to adequately mist new produce department layouts that increasingly utilize multi-deck casing. Suppliers are coming up with new designs that address that challenge, one Peterson sees as perhaps more urgent than issues of water quality.
"By and large, I think misting systems are handled safely in most retail operations across the country," he said.
Pure and Simple
Companies promising to deliver cleaner water to supermarket produce departments are billing their solutions as significant breakthroughs in water purification methods.
Both Electric Aquagenics Unlimited, which is teaming with a misting systems supplier for a beta test at selected supermarkets, and Radnor, Pa.-based Sterilox Technologies, which launched a product for supermarkets last year, employ technologies that utilize chemical reactions rather than chemicals.
EAU's Empowered Water Generators and Sterilox's A-2000 generator employ electrolytic technology to produce pathogen-killing water-based fluids that can be piped directly into the water supply used to feed misting systems, clean and crisp produce in the back room and wash down surfaces where food is prepared.
The process of electrolysis, which involves passing water and salt across electroplated cells, is a chemical reaction that produces acidic and alkaline fluids that, when mixed together, become a potent disinfectant capable of killing bacteria and mold and controlling the growth of organisms like E. coli and salmonella.
Both companies tout their products as ideal solutions to pathogen control because they don't use potentially toxic chemicals to kill bacteria. EAU President and CEO Gaylord Karren said the company's product has received regulatory approval for use on foods and has been deemed in line with the national organic standards.