Meat Processors Look for Ways to Keep Ground Beef Safe

By ANDREW MARTIN
nytimes.com

In the last decade, Tyson Fresh Meats has transformed its slaughterhouse here to combat a potentially deadly type of food poisoning, adding huge chambers to scald carcasses and wash them in acid, steam vacuums to suck away microbes and elaborate gear to test hundreds of meat samples a day.

In all, the beef industry says it spends upward of $350 million a year to keep harmful pathogens out of the meat it sells to the public. But even as expenditures keep rising, the industry appears to be losing ground.

Late last month, the Agriculture Department announced its 20th recall of beef this year because of contamination with a toxic strain of the bacterium E. coli. That is only one recall shy of a record set in 2000 and matched in 2002.

No one knows for sure what is causing the jump in recalls, though theories abound, from the cyclical nature of pathogens to changes in cattle-feeding practices caused by the popularity of ethanol.

This much is clear: Fifteen years after an outbreak at Jack in the Box restaurants made people aware that hamburgers could kill them, the American beef industry is still searching for a practical method to prevent the toxic E. coli strain from contaminating ground beef.

“If you gave me a million, zillion dollars and said give me a plant that doesn’t have E. coli, I couldn’t do it,” said Michael T. Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota. “It’s not about the will. It’s about the ability.”

What makes this year’s spate of recalls so surprising is that it comes after several years in which the number of recalls dropped sharply, to eight in 2006 and five in 2005. And it includes not just small and midsize firms with less rigorous food-safety protocols — like Topps Meat of New Jersey, which recalled 21.7 million pounds of frozen hamburger because of potential E. coli contamination — but also large companies that have spent tens of millions of dollars to prevent E. coli contamination. Topps closed its doors on Oct. 5, and declared bankruptcy late last month.

Tyson Fresh Meats, for one, has had two relatively minor recalls this year; there were no reported illnesses. Cargill Meat Solutions, which has won plaudits for its efforts to combat E. coli, has had two recalls, including one in October affecting about 845,000 pounds of ground beef that had made more than a dozen people sick.

The Agriculture Department issued new guidelines in October urging the meat industry to adopt the latest technology to combat harmful forms of E. coli — essentially the measures that Tyson already has in place. But department officials acknowledge that short of irradiating the meat, there is no magic bullet to prevent E. coli contamination.

“The big challenge for them is you are dealing with people and biological systems,” said Kenneth E. Petersen, assistant administrator for field operations for the Agriculture Department’s Food Safety and Inspection Service. “To execute the program consistently every hour of every day they operate, that’s the challenge. They do a pretty good job at it. You can’t take your eye off the ball for any period of time or you get into trouble.”

The federal government says it believes that exposing meat to radiation is a safe and effective way to kill E. coli and other pathogens. But meat companies have been hesitant to use irradiation because of fears that it would make meat more expensive, change the taste and color, and provoke consumer opposition.

Escherichia coli bacteria are commonly found in the lower digestive tract of humans and animals, and they are usually harmless. But one strain, E. coli 0157:H7, produces a toxin that can make people sick, typically after eating ground beef or produce that has been contaminated by cattle feces.

It is difficult to say whether the amount of E. coli in ground beef has increased this year, since the number of recalls is an imperfect measure. Limited sampling by the Agriculture Department has found a slight increase in the level of E. coli 0157:H7 this year over recent years, though it remains lower than it was five or six years ago.

But some meat industry officials say they are sure that more E. coli is turning up in cattle this year. That impression is shared by William Marler, a lawyer in Seattle who specializes in food-borne illness and who has seen a marked increase in clients who say they became sick from eating E. coli-contaminated meat.

“This is real stuff,” he said. “It is a fundamentally different year than ’06, ’05, ’04 and ’03.”
As part of its efforts to eradicate E. coli, the meat industry is experimenting with vaccines, antibiotics and feed additives that may reduce the level of E. coli 0157:H7 in cattle intestines. But so far, those are not commercially available. To date, nearly all of the efforts to curb E. coli have focused on interventions at slaughterhouses and at grinding plants that produce ground beef.

Hamburger meat poses an elevated risk of illness because grinding can mix live E. coli bacteria throughout the meat, and consumers often undercook their hamburgers. Steaks pose less of a risk because any E. coli on the surface are likely to be killed during cooking.

Mohammad Koohmaraie, director of the Agriculture Department’s U.S. Meat Animal Research Center in Nebraska, said his research had determined that most E. coli contamination came from the hides of cattle, which became matted with mud and manure in feed lots. As a result, his research has focused on ways to reduce the likelihood that manure from the hides comes in contact with a carcass during slaughter and subsequent handling.

“If you don’t do a good job of removing the hide, a whole bunch of it gets on the carcass,” Mr. Koohmaraie said. “If you do a good job, just a little bit to none gets on the carcass.”

His research, for instance, found that spraying the hides of cattle with a chemical wash immediately after they are killed drastically reduces the incidence of E. coli 0157:H7. JBS Swift & Company and Cargill are now using hide-washing procedures, which can cost several million dollars to install.

Dean A. Danilson, Tyson’s vice president for food safety and quality assurance, said that his company might install hide-washing equipment as it built new plants or retrofitted old ones. In the meantime, in the rear of the Lexington plant, a former combine factory converted to a slaughterhouse, an employee in rain gear hoses down cattle in a pen before they are slaughtered to rinse away manure and limit the amount of dust when the hide is removed.

“Keeping the dust down, knocking some of the caked-on mud and things off, any little bit helps,” Mr. Danilson said.

It is the first of many steps that Tyson employs to reduce the chances that pathogens like E. coli survive processing. Once the animal is killed, the hide is removed, first by knives and then by machines, in a manner intended to keep it away from the exposed carcass, starting near the anus and hind legs.

After each cut is made to remove the hide, a worker follows behind with a steam vacuum to kill and suck away microbes. The carcass, pulled along on an overhead rail, is then sent into a cabinet with pivoting nozzles that soak it with water at about 185 degrees.

After the head is removed and before the animal is gutted, the carcass is sprayed with a mild acid wash, again to reduce the level of microbes. Besides removing the hide, one of the most critical steps to prevent E. coli 0157:H7 comes when the animal is eviscerated and its internal organs are removed.

The workers who remove the organs are careful not to cut the bowel, which could spread manure, and a worker looks over the internal organs to make sure the intestines are intact. The carcasses are then sawed in half, and the cut line is steam vacuumed.
In one of the most important interventions, the split carcasses are sent into a 30-foot-long, hissing stainless-steel cabinet, where rows of nozzles spray them with steam for at least 13 seconds before they enter a second chamber that douses them with a disinfectant for at least 15 seconds.

The last step comes after the carcasses have been cut into steaks and roasts and leftover scraps, with the latter tossed into 2,000-pound bins for grinding into hamburger meat. Workers are assigned to cut at least 60 four-inch by one-half-inch strips from each lot of trimmings; a lot is five 2,000-pound bins.

Those samples are then ferried to a laboratory, where they are mixed with solution that encourages E. coli 0157:H7 to grow. After incubating for eight hours, the samples are tested, and if positive for the germ, that lot is diverted from being used as ground beef. Instead, it is used in cooked products or otherwise processed to kill the microbes.

“I wish I had a silver bullet. We have done a lot, and it’s a continuing ongoing process to look for more,” Mr. Danilson said. But he acknowledged that it was impossible to create a perfect system for stopping E. coli 0157:H7. “Taking a dirty animal and turning it into food — from the time of the cave man, that has not been an easy process.”

Source:
http://www.nytimes.com/2007/12/06/business/06meat.html?ref=health
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