PREFER YOUR STEAK BATHED OR
ZAPPED?
ADDED ATTENTION TO ELIMINATING
DANGEROUS BACTERIA IN FOOD HAS GIVEN
RISE TO A
By Jon Van, Tribune Staff Writer
Web-posted Monday, December 8, 1997; 6:01 a.m. CST
Like generals huddled in a war room, food industry executives are
evaluating their arsenals in search of weaponry to counter the
microbial mayhem visited on Americans in a spate of high-profile
food poisoning outbreaks.
Although the familiar, but mostly unused, nuclear option still beckons,
some newly minted conventional weapons may offer impressive
killing power in an easier-to-deploy package. Why nuke bugs with
radiation when a steam sizzle or ozone bath may be just as lethal?
Food irradiation still faces plenty of obstacles, but it can't be ignored
in the nation's war on victuals villains, especially given the law signed
by President Clinton in November that eases label requirements for
irradiated foods and last week's Food and Drug Administration
approval of irradiation to treat beef.
About the only certainty these days in the war on meat-spoiling
microbes is that big guns are poised to enter the fray, and the industry
is eager to use whatever will it takes to avoid another incident like the
one that shut down the Hudson Foods Inc. plant in Nebraska last
summer.
One reason for the urgent attention in the industry stems from new
genetic-tracing technology that enables public health agencies to
identify particular families of troublemaking microbes with great
precision. Starting with the victims, they can trace specific
contaminants back to restaurants and processing plants, which helped
pin the tail on Hudson Foods.
Before long, individual slaughterhouses and perhaps even farmers and
ranchers may bear the ultimate stigma of introducing pathogens into
the food chain, a real incentive for them to improve cleanliness.
"The real driving force behind pushing food safety improvements is
the fast-food restaurants," said Dan Murphy, business editor of Meat
Marketing & Technology magazine. "When you have
Jack-in-the-Box, McDonald's and Burger King all demanding their
suppliers keep records to trace this back, you can see where it's
going.
"It forces the slaughterhouses to assure that when they sell (beef
carcass) trimmings (for grinding into hamburger) they aren't
contaminated."
The technology to use radiation to zap meat and kill contaminants has
been around for decades, but it hasn't been used much. So far, the
industry remains slow to embrace irradiation, despite its proven killing
power and friends in Washington.
Instead, slaughterhouses seem more inclined to install a new
technology that sprays beef carcasses for a few seconds with
high-pressure steam to eradicate bacteria.
Steam pasteurization doesn't carry the negative consumer perceptions
associated with irradiation, and it appears lethal enough to do the job.
Cargill Inc., the giant food processor based in Minneapolis, is the
leading proponent of steam pasteurization, having helped
Frigoscandia Equipment Group, a Swedish company, develop the
technology.
Although it can cost roughly $1 million to install a steam treatment
system in a meat plant, that works out to much less than a penny per
pound of meat over the life of the system, at least for the really large
processing plants, said Jerry Leising, director of research for Excel
Corp., Cargill's meat-processing subsidiary.
"We see this as a cost of doing business," Leising said. "If we can
enhance consumer confidence in our product, beef demand will rise."
But steam isn't alone as an alternative to irradiation in the war on
microbial meat menaces. Another aspiring bacteria-slayer is ozone,
the form of oxygen that is highly reactive with other molecules.
Cyclopss Corp. of Salt Lake City and its president, Bill Stoddard,
are ozone's chief proponents, receiving major assistance from the
electrical utilities industry through its research arm, the Electric Power
Research Institute.
Ozone can be made from common oxygen with the application of
electricity, which interests the utilities enough to cause them to help
conduct research that convinced the Food and Drug Administration
that ozone should be accepted as a food treatment technology.
Cyclopss, which now uses ozone to sterilize medical equipment and
other products, has pilot tests under way with some food processors
and hopes that by sometime next year it will have proposed
guidelines to offer the Department of Agriculture for ozone food
sterilization.
It isn't difficult to incorporate ozone into current treatment processes,
Stoddard said, because the gas can be infused into water that is
already used to clean meat or vegetables.
The main obstacle is to determine such things as the amount of ozone
and time of immersion necessary to treat various kinds of food.
Without establishing such guidelines, Stoddard said, processors might
apply ozone ineffectively and give the technology a bad name.
"Lots of companies make equipment that generates ozone," Stoddard
said. "It's used in bleaching paper, for instance, but just because you
can make ozone doesn't mean you know how to use it to sterilize
food."
Stoddard said he believes the clamor for safer food will benefit ozone
and, perhaps, other new technologies, but that food irradiation will
remain a virtual non-starter. His firm has even run some national
advertising to promote this view.
Not that irradiation doesn't have its champions.
Last Tuesday, for example, saw an endorsement of food irradiation
by Michael Osterholm, Minnesota state epidemiologist and a widely
respected investigator of food poisoning.
"We do not have a 'kill' step for much of our food supply that's
adequate to get rid of bacterial and parasitic pathogens before they
get to the consumer," Osterholm said at a public health briefing
sponsored by the American Medical Association and the American
Public Health Association. "Ionizing pasteurization will clearly do that
for meat and poultry and some produce."
But even to its champions, some flaws of food irradiation are
apparent.
"It goes back to Three Mile Island, a very strong anti-nuclear
sentiment in this country," said Richard Lechowich, director of the
Illinois Institute of Technology's National Center for Food Safety and
Technology. "It frightens people."
And although most scientists argue that irradiating food is perfectly
safe, it can cause meat to be less marketable.
Studies at Iowa State University have shown some changes in the
color and odor of meat wrapped in plastic and then irradiated, said
Dennis Olson, director of Iowa State's linear accelerator facility.
"After irradiation, when you open the package, an odor is
detectable," Olson said. "Its intensity varies with the type of wrapping
material used, and we're trying to understand the chemistry causing
this. These changes aren't real big and they're eliminated once the
product is cooked."
Still, it doesn't inspire a lot of confidence among food marketers.
Jim Corrigan, who operates the Carrot Top food store in
Northbrook, may be one of the country's biggest boosters of
irradiated food. But he also recognizes some problems.
Corrigan sold irradiated chickens after the FDA approved the
process for poultry in 1990. Corrigan found high customer
acceptance, but he no longer sells the chicken because his supplier
stopped shipping in lots small enough to accommodate his needs.
Some beef processors have asked if Corrigan would like to
participate in test marketing irradiated beef, now that it has FDA
approval.
"I don't object to being in a test," he said, "but if the product is
successful, I'd like a commitment to keep getting a supply I can sell.
I'm not in this just for the science. I want to make money at it. When
you have a product and then you don't, customers start to wonder
why. In the case of irradiated chicken, we had it for about a year and
a half, and then we didn't."
One of Corrigan's customers, Mary Pardini of Northbrook, said that
she is very worried about food poisoning and would like to buy
irradiated meats.
"I think we need to have that choice," she said, "but there's so much
ignorance out there, we don't have it."
Many experts believe marketing and economic issues could still
prevent food irradiation from becoming a widespread option.
Michael Colby, executive director of Food and Water, an
anti-irradiation group based in Walden, Vt., called it outrageous that
Congress passed a law allowing food to be irradiated and carry no
special notice larger than the fine print used to describe ingredients.
"Ninety percent of Americans polled say they want a notice on
irradiated food," he said.
But Colby said that he doubts that processors will try to sneak
irradiated foods into markets because they know that his group and
others would advertise it and promote a backlash.
"Any corporation that plays around with this is going to get burnt," he
said.
"We're confident we're going to win."
METHODS ATTACK ON ALL FRONTS
Here's how three food purification methods work:
Irradiation
Food irradiation comes in several different packages, and even
though the basic technology has been known for decades,
researchers continue to explore new ways to use it.
The goal is to bombard food with ionizing radiation that produces
electrical charges within the cells of pathogens that may be living on
the surface of the food. Ionizing radiation breaks apart molecules
within microbes, resulting in the organism's death, inability to function
or failure to reproduce, rendering the bug harmless to humans.
In a stand-alone facility, a stream of gamma rays generated by small
rods of radioactive cobalt-60 may do the job. But this means that the
food being treated, whether strawberries or chicken, must be brought
to the site.
Gray Star, a firm based in Mt. Arlington, N.J., is developing a unit
meant to be installed on-site in a meat processing plant that uses
cesium-137 to produce gamma rays, and they estimate it may be a
year until a prototype will be ready for testing.
Another form of ionizing radiation, called electron beams, can be
generated by linear accelerators. They work like TV picture tubes,
producing electrons from a heated filament and accelerating them
with a magnetic field.
Although electrons don't penetrate as deeply as gamma rays, Dennis
Olson, an Iowa State University food science professor, said electron
beams generated above and below a product could treat hamburger
patties or chicken parts up to three inches thick.
Steam
An alternative to irradiation is to spray a film of steam over a carcass
for a few seconds just before using chilled water to cool the meat as
it enters a chiller. The heat from the steam coagulates the cells of bugs
residing on the cell surface, making them rigid and killing the bacteria.
"You can see coagulation at work when you break an egg into a hot
frying pan," said Jerry Leising, a research director at Cargill Inc.,
which developed steam pasteurization.
Although microbes that encounter the steam will die, the treatment is
so quick that it doesn't cook the meat, he said.
Ozone
Another new technology to sterilize food centers on ozone, which is a
highly reactive form of oxygen consisting of three oxygen atoms
instead of two. Ozone can be infused in water used to soak
carcasses during processing, said Bill Stoddard, president of
Cyclopss Corp., an ozone technology developer. Ozone is created
by exposing regular oxygen to electrical energy.
Ozone is a rampant promoter of oxidation, the process seen as rust in
metal. When a molecule of ozone encounters organic molecules in the
cell of a bacterium, the oxygen combines with carbon, breaking apart
the molecule.
"It literally chews right through cell walls," Stoddard said.
Major byproducts of the process are carbon dioxide and water. |
