Beyond chlorine: whether to improve microbial kills or operational safety, processors are taking a harder look at chlorine alternatives.
Options have exploded in recent years, however, with development of - and FDA approval for - a variety of alternatives, from relatively low-tech ozone to ultraviolet radiation and new chemicals, such as Ecolab Inc.'s Tsunami.
All the alternatives to chlorine share one major drawback - they all cost more, at least at the outset. They either require some additional capital outlay running into the thousands of dollars, or they require chemicals costlier than abundant, cheap chlorine.
But whether for environmental compliance issues or because of concerns about the effectiveness of chlorine, processors are starting to take a hard look at alternatives, and in some cases adopting the technology.
Chlorine has served the food and beverage industry for years - and it's cheap. Those two factors weigh heavily in its favor and still make it the disinfectant of choice in many places.
But chlorine comes with a variety of problems. In water with high levels of organic residue, chlorine dissipates quickly. Using too much chlorine to compensate, however, can lead to formation of excessive hypochlorous acid that causes chlorine to volatize more rapidly, creating fumes that can pose hazards to plant workers. Finding the right level of chlorine needed to kill all the microorganisms without leaving too much chlorine or volatile fumes behind can be difficult.
Agrilink Foods, a processor of frozen vegetables, has switched to Ecolab's Tsunami, or peroxyacetic acid, for treatment of process water in many of its plants in the past two years largely because of concerns about the effectiveness of chlorine, says Roger Brown, director of analytical technologies for Agrilink in Benton Harbor, Mich. Following Agrilink's acquisition of Dean Foods' frozen vegetable processing facilities earlier this year, Brown felt vindicated by finding that Dean, too, already had made the switch to Tsunami in several facilities.
"We had issues where the chlorine would easily break down with organic matter (in the flume water)," Brown says. "Chlorine is not effective in sunlight, and it's not effective if it warms up much above room temperature. It breaks down fairly quickly. I've dealt with plants in the past where they would check for chlorine levels right after they injected it instead of waiting to get it in the end of the stream, because there was never any chlorine left (by that point). And the chlorine (fumes) were strong enough to knock you over. So, chlorine is a lousy disinfectant."
The only problem Brown has with Tsunami is the cost. "You don't want to use it in a system where you're constantly adding water," Brown says. "If you have a system that's closed loop and you're basically just moving vegetables from point A to B in a post-blanch operation, it's wonderful. You use low amounts of the peroxyacetic acid, and the residual stays long-term, and as long as you have that final rinse (with potable water), it's very effective. The microbial counts have been reduced up to 50 percent in some places (over treatment with chlorine), and we're very happy with it.
"My only problem is that we've got plants that took off and used it so rapidly that we didn't always have a chance to study the microbial reduction and to see whether there's not a lot of makeup water coming in - and then they come back and say how expensive it is. And then we look at the application and find out it probably should not be used in this application."
Tsunami does cost 50 to 100 percent more than chlorine, depending on the application, says Nick Alfonso, director of food and beverage marketing for Ecolab. But he says Tsunami makes up for the cost with improved microbial control and safety.
Handle with care
Tsunami may not present as many safety issues as chlorine, but - like most control measures - it can present risks when mishandled. It's a corrosive chemical that shouldn't be handled directly. And in one California plant, workers left a drum of Tsunami open, allowing fumes into a ventilation system. Alfonso says. Some plant workers were temporarily overcome with fumes and the plant had to be evacuated, but no one was seriously injured, he says.
"Like any other chemical, you have to take care when you handle it," Alfonso says."That's why we built around the system what we call a 'no touch' sensing system, so really in practice a human being never has to touch the product. We supply our customers with a controller and a pump. And the only thing that needs to be done is put a pickup tube into the drum, set the controller, and it dispenses the material automatically."
After winning widespread use in processed produce applications, Ecolab received FDA approval in May for Tsunami to be used in fresh produce processing.
Safety and environmental issues aren't driving Handi-Pak Foods Inc., a Kankakee, Ill., fresh vegetable processor, to experiment with Tsunami, but the prospects for improved microbiological kill and shelf life are, says Ryan Sparrow, vice president of operations.
"The only problem with Tsunami is that it's quite a bit more money, so you really have to justify it," Sparrow says. "I would use it if we would really have significantly better shelf life. But if I use it, it would probably be in conjunction (with chlorine), adding another step."
In California, many vegetable processors have been seriously testing or adopting ozone in their process water, says Dee Graham, a microbiologist, president of the consulting firm R and D Enterprises and chair of the independent panel of experts who declared GRAS status for ozone in June.
Wary on ozone
Manufacturers adopting ozone are reluctant to talk about it, either because they view their switch as a technological edge or because they are wary of the regulatory status of ozone. Though ozone has GRAS status by virtue of the review of independent experts, that wasn't published in the Federal Register because the FDA isn't required to publish such findings, Graham says. Other companies are reluctant to talk about use of ozone because they were actually using the process before ozone received GRAS status.
"Some of the original equipment manufacturers are shipping one or two (ozone) systems a week, and most of the shops I have any reason to be in contact with are pretty busy," Graham says. "There's a lot of evaluation going on in the fresh-cut industry. At least two or three companies in the meat industry are testing (ozone)."
He sees processors considering ozone primarily because of increased regulations for handling chlorine in some states, such as California, or because of concerns about how effective chlorine is in combating pathogens.
Brown says Agrilink did test use of ozone in one plant during one month this year. Ultimately, the plant decided against using it because it wasn't as effective in reducing pathogens as Tsunami.
"We were leasing (the ozone-generating equipment)," Brown says, "and I don't think the plant would try to go to the capital well to get the dollars required."
One emerging alternative Agrilink hasn't tried is ultraviolet radiation, which Brown sees as a potentially promising disinfectant technology, albeit a hard sell. Ultraviolet "should be effective," Brown says, but he hasn't seen any research from Agrilink's own plants to indicate the degree of microbial reduction that can be attained. "We never got anyone to bite" on trying the UV technology at the plant level, he says. "Plant managers like chemicals. We have this false sense of security that chemicals do something better."
Aquionics, an Erlanger, Ky., manufacturer of UV technology, is seeing considerable interest from the food and beverage industry, says Ralph Lopez, food and beverage marketing director. That interest extends to use of UV as a sole disinfectant method to replace chlorine rather than a supplementary tool.
"We're dealing with all the major players and brand leaders in the industry," Lopez says, though he declined to provide specific manufacturers' names, citing confidentiality concerns.
For many processors, chlorine is going to remain the tool of choice, Agrilink's Brown says. In vegetable processing, stronger measures are the most necessary in processing spinach, greens and other crops that grow in or low to the ground and pick up more than their share of microbial contaminants. For such crops as corn or fruits, chlorine is more likely to provide adequate control.
"If you're finding chlorine to be effective and you're able to use it as a tool, that's fine," Brown says. "We find certain applications and processes where you really need (something stronger), and other places where it's not so critical. I wouldn't say anything is the magic bullet, but the choices are a lot better today than they were a couple of years ago."
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|Title Annotation:||food processors|
|Date:||Jan 1, 1999|
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