The Food Safety Consortium Newsletter
Vol. 10 No. 2
Spring 2000

U Brings in a Stork to Insure Safety

A stainless steel tower about 12 feet tall with billows of steam blowing out the sides may be an answer for companies trying to maintain the safety of their processed meats.
The pasteurization unit at Kansas State University sits in a sterile room held to the same environmental standards as a surgical operating facility. But in this room, the goal is to keep harmful bacteria out of cooked and ready-to-eat meats that have already been packaged.
James Marsden, a Food Safety Consortium researcher at KSU, explained that the problem processing plants face is that ready-to-eat meats could become recontaminated on the surface after cooking before the final packaging procedures. Processors use thermal processing procedures to eliminate pathogens during the cooking process. The snag can come when it's time for packaging and a piece of meat that has already been cooked to control pathogenic bacteria can become recontaminated.
"Processed, ready-to-eat meat and poultry products are usually fully cooked and food safety concerns for these products result from recontamination of the product surface with the pathogen Listeria monocytogenes after cooking, but before packaging," said Curtis Kastner, the FSC program director at Kansas State.
Kansas State worked with Stork RMS Protecon Corp. of Gainesville, Ga., and Steris Corp. of Menton, Ohio, to develop a steam pasteurization unit that can eliminate any recontamination that has occurred during packaging. They also collaborated to build the clean-room environment necessary for the unit's success.
"Through the application of post-process pasteurization, contamination of the surface of processed meat products can be virtually eliminated," Kastner said. "For sliced processed products, Stork's post-process pasteurization technology is combined with Steris' clean-room technology that results in a product that is pasteurized and then sliced and packaged in an aseptic environment, preventing recontamination."
Kansas State researchers test the unit by placing a wrapped and packaged portion of cooked ready-to-eat meat in the unit. The scientists try varying levels of exposure time and temperature to determine what combination will work most efficiently to penetrate the wrapping and kill any pathogens on the surface of the meat.
"Since post-process contamination is limited to the outer surface of processed meats, the combination of these technologies should effectively control Listeria monocytogenes and other foodborne pathogens," Marsden said. "This approach, which involves thermal processing, may be an alternative to irradiation for improving the safety of hams, hot dogs, roast beef and other processed meat products."
Irradiation is not currently authorized by federal regulators for applicaton to ready-to-eat meats. A petition is pending that seeks government approval of the process for ready-to-eat meats, but it could be months to years before any approval may be granted.
The Stork unit is a new condensing steam pasteurization technology developed in conjunction with Steris' design of the clean-room environment. The combination makes it probable that the surface of food will not become recontaminated while a pasteurized product is being packaged.
With Kansas State testing the unit, scientists will be able to evaluate more accurately the microbiological effects of condensed steam pasteurization on ready-to-eat meats, said Bill R. Sanford, chairman of Steris.
"This integrated solutions approach combines the sue of products and technologies for monitoring, reducing and preventing potential contamination at all stages throughout the food producton process," Sanford said. "The ability to control microbiological contamination in the air, on hard surfaces or on the hands of workers is critical to providing food that is contamination free."

ew Irradiation Rules Open New Opportunities
It is now legal to irradiate and market refrigerated or frozen raw meat and meat products. New federal regulations went into effect in February, capping a rulemaking process that took years.
Irradiated meat is still a rare sight in the nation's grocery stores. The market is taking time to survey the situation, but industry isn't being idle in the background.
"The whole impetus for moving forward is E. coli 0157:H7 in ground beef" said Dennis Olson, a Food Safety Consortium researcher at Iowa State University. "The companies are saying that irradiation is another tool that we can use to ensure the safety of our product. The poultry people are coming right on board and saying they are not going to be out there by themselves any more. Poultry's issues --- Salmonella and Campylobacter --- are important. The advantage of increased shelf life from irradiation is tremendous."
Before the irradiated products begin making their way to the stores, the meat industry and the irradiation industry are forming some alliances. In 1999, Tyson Foods, the world's largest poultry processor, contracted with Titan, Inc., to use Titan's irradiation technology. Zero Mountain, Inc., a Fort Smith, Ark., cold storage company with poultry industry clients, has announced that it will build an irradiation facility in Arkansas using Titan's technology.
Titan has constructed an irradiation facility in Sioux City, Iowa, which will be used by Tyson; Iowa Beef Packers (IBP), the nation's largest ground beef producer, and Cargill Foods, the second largest ground beef producer, and others. Titan has also allied with Cloverleaf Cold Storage of Sioux City to provide refrigerated food staging, storage and processing facilities and logistical support for Titan's new food pasteurization processing system.
Olson said it's too soon to tell for certain how the situation will evolve, but he predicted that more irradiation facilities will be built on site at processors' plants so they won't have to transport their product.
"As they look at competition for this consumer market that wants irradiated food, the costs are going to become more important," Olson said. "If IBP is doing 50 million pounds at its Sioux City plant and it has the ability to do 150 million pounds, it will probably build on site if it can't get enough capacity. At Zero Mountain or at Cloverleaf you have small and medium-size operations that can have contract irradiation."
Other issues related to irradiation remain to be resolved. Olson calls the use of packaging materials "the big looming issue."
Current packaging materials for meats are acceptable for use with irradiated meat, but the meat industry would prefer to implement packaging that is specially designed to withstand doses of irradiation and still allow the product to appear natural. The Food and Drug Administration must approve any new packaging and is considering petitions from companies.
"My perception is that the only thing that will slow the rapid growth of irradiated foods will be packaging issues," Olson said. "Industry has some packaging materials they can start out with, but not really the kind of material they would like to use to present the product to the consumer."
The industry also wants to see irradiation authorized for cooked ready-to-eat meat products, but that means another petition must make its way through the regulatory process. That's often been a procedure that could take up to five years, but a revision in rulemaking may speed up the timetable.
Under the previous method, after FDA approved a petition from the meat industry it would be sent to the U.S. Department of Agriculture for further consideration. Since December, the process has been changed so that USDA and FDA work on their issues simultaneously and only one approval, issued by FDA, is necessary for a petition to be approved.
"Fast-tracking" is another factor that may move the process along for approval of irradiation of ready-to-eat meats. Olson explained that FDA now is using its authority to put a petition on the fast track, which could reduce the time under consideration to a year.

Consumer Support Seen for Biotechnology, Irradiation
Consumer acceptance of biotechnology in the United States food industry indicates a relatively high level of confidence by the American public in farmers, food companies and government, according to spokesmen for two national food industry organizations.
David Schmidt, senior vice president for food safety, International Food Information Council (IFIC) and Kelly Johnston, executive vice president of the National Food Processors Association (NFPA), both based in Washington, spoke at the Ozark Food Processors Association convention in late March in Springdale, Ark.
Johnston said the NFPA helped President Theodore Roosevelt get the Pure Food Act of 1906 through Congress and has had a close, though often stormy, relationship with government regulatory agencies ever since.
Schmidt said polls and focus group studies reveal that American consumers make good decisions about products when they have complete information on issues such as biotechnology, irradiation, pesticides and other food safety and nutrition issues.
When presented with science-based information, most consumers accurately distinguish between "perceived" and "actual" issues, Johnston said.
"Consumers correctly identify microbial foodborne illness as the No. 1 food safety concern. That is a real issue based on scientific evidence," he said.
Schmidt and Johnston said a major exception to the public's accurate response to food safety concerns is on the issue of irradiation. They said unjustified fear of irradiation to kill microorganisms in food has resulted from several decades of inaction by both industry and government to inform the public on that issue.
Schmidt said focus group studies indicate that recent government policy statements on the safety of irradiation and educational efforts by the industry will lead to its acceptance as a safe and highly effective method of killing harmful bacteria in food.
Both men said the use of biotechnology to produce better, healthier and less expensive food may be delayed by inadequate response to unjustified fears.
"I see a disturbing parallel between irradiation and biotechnology," Johnston said, in the difficulty of communicating science-based information to respond to unsubstantiated fears promoted by opponents of biotechnology in food production.
"Labeling is a huge issue," he added.
He said any labeling requirement to draw undue attention to use of irradiation or biotechnology in a food product would create the inaccurate perception of "a warning."
Schmidt said focus groups don't like the word irradiation, "but they like the result of irradiation making food safer to eat." He said the term "cold pasteurization" accurately describes the effect of irradiation.
"Consumers in focus groups like the idea of a food label that says 'cold pasteurization' and then 'irradiation' in parentheses," Schmidt said. "That gives them a positive, accurate description of the process and its effect without hiding the fact that irradiation was used in the process."

ort From the Coordinator
Charles J. Scifres
The federal Centers for Disease Control recently published a brief history of achievements in public health in the past century, including a focus on food safety. As we become caught up in the details of contemporary issues, it is helpful to regain some perspective by looking at what brought us to this point in our progress.
We have to go back a couple of generations to see what a different world it was. The CDC report recalls that 100 years ago, consumers kept their food fresh by placing it on a block of ice during warm weather or on a window sill during the winter. The unsanitary working environment in the meatpacking industry was coming to light with the publication of Upton Sinclair's book, The Jungle. Typhoid fever, tuberculosis, botulism and scarlet fever were frequently caused by foodborne infections.
By the 1920s, conditions improved with the availability of household refrigerators with freezers. Milk producers were implementing pasteurization of their product. As the century advanced, scientific research identified foodborne pathogens and ways to control them. In the modern era, science found it could not rest as newly recognized foodborne pathogens have been emerging since the 1970s as agricultural practices and food processing operations have changed. The spotlight on animal health has intensified.
Researchers in industry, government and academia have responded with new approaches to new problems. Hazard Analysis and Critical Control Points systems have been developed. Improvements in surveillance and investigations of outbreaks have led to new ways to control pathogens.
Predicting the future should always be done cautiously, but the CDC document offers this much of a glimpse: "Any 21st century improvement will be accelerated by new diagnostic techniques and the rapid exchange of information through use of electronic networks and the Internet."
As improvements in food safety make their way through the farm-to-table system, food safety researchers have their continuing responsibilities plus some new ones. The Center for Food and Nutrition Policy at Georgetown University advises us that increased communication of risk analysis will be vital and must be based on sound science. Risk communications must be delivered so that the general public will appreciate and understand its message. The messengers must be not only the research community but also public schools and the health professions. Partnerships will be the foundation of food safety in the years to come.
In that regard, we can all take pride in the Food Safety Consortium, a 10-year partnetship which represents one of the most productive collaborations of its kind.

Early Detection of Salmonella Aids Processors
Researchers at the University of Arkansas have found a way to detect as few as 5,000 Salmonella bacteria from a chicken carcass sample in two hours. Their detection method may one day lead to faster, more sensitive and more comprehensive biological sensors in the food industry.

Yanbin Li, professor biological and agricultural engineering; Michael Slavik, professor of poultry science, and David Paul, professor of chemistry, will publish their findings in an upcoming issue of the Journal of Food Protection. Li and Slavik are also principal investigators with the Food Safety Consortium.

The Centers for Disease Control and Prevention in Atlanta estimate that every year, 800,000 to 2 million people experience the fever, cramps and diarrhea that accompany a Salmonella typhimurium  infection. Most of those afflicted contract the disease through  contaminated food or water.

While such food poisoning can be prevented by thoroughly cooking meat, the University of Arkansas researchers are trying to build a detector that would "find Salmonella on the spot" before the meat ever leaves the packing plant.

"After two hours, the sampled food may be in the factory," Slavik said.
This could save consumers from buying contaminated foods and manufacturers from making costly recalls.

Li , Slavik and Paul are pooling their expertise in bioinstrumentation and food processing, bacteriology, and sensors to create an on-site biosensor that can detect Salmonella.

"Biosensors are the better way to get to on-line, real-time detection of bacterial contamination in processing plants," Li said.

The current culture method of Salmonella detection requires swabbing the meat and growing the bacteria for three days, an unrealistic practice for a processing plant that may process and send out millions of chickens each day.

To speed up the detection process, the researchers collect the sample by shaking a chicken carcass in a plastic bag with a buffer. They put the buffer mixture into a test tube filled with small magnetic beads coated with antibodies that bind a specific Salmonella strain. The scientists wash the mixture with another buffer, using a magnet to pull the beads over to one side with the Salmonella bound to the antibody.

Then they add an enzyme labeled antibody which attaches to the Salmonella typhimurium bacteria. They wash the excess enzyme off, again using the magnetic beads to keep the antibody bacteria-enzyme sandwich intact.

The scientists add phenyl phosphate to the mixture. The enzyme attached to the bacteria chops up the phenyl phosphate to create phenol, which can be detected by an electrode. The reaction takes place in less than an hour, and the amount of phenol produced is directly proportional to the amount of bacteria in the sample.

Using this method, as few as 5,000 bacteria can be detected in two hours, with a flow injection system.

The scientists continue to look at ways to speed up the detection process and detect fewer and fewer bacteria, Li said. They will focus on microbial, engineering and chemical methods to speed up the reaction time. They will also try to reduce non-specific binding to the antibodies, which will increase the test's sensitivity.

Although better detection methods can help reduce the incidence of Salmonella in raw animal products, it won't eliminate the problem of foodborne illness. A detector could never guarantee that the entire volume of meat processed in the average processing plant is Salmonella- free, Slavik said, because only a small portion of the meat processed on a given day can be tested. Salmonella contamination can also occur after the meat has left the processing plant from unwashed hands and cross-contamination while preparing foods.

"The only thing we can do is try to make sure there are no bacteria on the tested carcass when it leaves the plant," Paul said.

Rapid Methods Workshop Observes 20 Years
Kansas State University's International Rapid Methods and Automation in Microbiology Workshop will be held July 6 to 14 at in Manhattan, Kan. This year's workshop is the 20th anniversary of the event, which is directed by Daniel Fung, a food science professor and Food Safety Consortium researcher at KSU. Randall Phebus, a KSU associate professor of food science and FSC researcher, is the workshop's assistant director.
The workshop focuses on the practical application of conventional and new commercial systems of rapid identification of microorganisms from medical specimens, food, water and the environment. Workshop participants receive eight days of intensive theoretical and hands-on training in microbiological automation. The workshop is designed for microbiologists, food scientists, medical technologists, consultants, quality assurance and control managers, laboratory directors and researchers.
The event includes a mini-symposium July 6 to 8 for those participants who do not wish to enroll in the full nine-day workshop. The July 6 session will include a celebration of the workshop's 20th anniversary.
Visiting professors for the workshop will be Millicent C. Goldschmidt, professor at the Dental Science Institute of the University of Texas Health Science Center in Houston; J. Stanley Bailey, a research microbiologist with the U.S. Department of Agriculture and an adjunct professor of poultry science at the University of Georgia, and Nelson A. Cox, a USDA poultry research microbiologist.
Information about registration and fees is available on the conference web site at An on-line registration form and a printed registrations form that can mailed or faxed are available at the web site. Information is also available by calling 1-800-432-8222 inside the U.S. or 785-532-5575 from outside the U.S.

A Search and Destroy Mission for Injured Bacteria

It's the start of a new year and in a lab in the Iowa State University Food Sciences Building, Aubrey Mendonca is putting bacteria on a diet --- a starvation diet.
"We take them from nutrient-rich media and put them in nutrient-poor media," says Mendonca, a food safety microbiologist and Food Safety Consortium researcher. "For bacteria, the change is like living on feasts every day, then one day waking up in a famine."
Mendonca (pronounced Men-DON-sah) is studying how disease-causing bacteria like E. coli 0157:H7 and Listeria monocytogenes adapt to stress, like starving conditions. Stress-toughened pathogens may pose new food safety problems.
"Understanding more about these pathogens may provide us with an extra margin of food safety," he says. "This is particularly important to the growing segment of our population that have weak immune systems. These include the elderly, the very young, those battling cancer or AIDS and those who've received organ transplants. What may be a mild food-related illness to healthy people could be a life-threatening one to them."
Mendonca has found that what doesn't kill microbes can make them stronger.
"Often what we microbiologists study are pampered lab microbes grown under optimum conditions," he says. "We've assumed such conditions provide us with strong organisms that are resistant to food-preservation methods. But this assumption is dubious because bacteria that have adapted to stresses, like mild heating or starvation, show more resistance than microorganisms that aren't adapted."
The starvation diet mimics a potential scenario in processing plants. "There may be bacteria that cling to equipment for several days without food," Mendonca says. "If they adapt to the stress and come in contact with food again, it's likely they'll be tougher to destroy."
Mendonca joined the ISU faculty in 1998. He previously had worked at North Carolina A&T State University, where he developed a microbial food safety program. Prior to that, as a post-doctoral scientist at Penn State, he first became interested in injured microbes --- those that survive the battering of food processing.
"Injured bacteria are a problem because they aren't easily detected by conventional methods for ensuring foods are pathogen-free," he says.
Mendonca explained why this was true for heat-injured bacteria. Microorganisms (and people, too) produce toxic byproducts derived from their use of oxygen. Microbial cells (and cells in our bodies) make enzymes that detoxify these byproducts.
When foods are heated during processing, such as milk during pasteurization, the heat kills most bacteria. Some survive, but their detoxifying enzymes have been destroyed. Without them, injured microbes can't handle oxygen, and will die.
After processing, methods to detect pathogens involve aerobic incubation. In the now-deadly open air, injured microbes won't grow. So they can slip past the radar.
Now here's the insidious part.
"Many meat products today are vacuum-packaged," says Mendonca. "The airless conditions shield the injured microbes from the oxygen that would kill them. The packaging provides a perfect environment for the pathogens to repair themselves and regain their virulence. When the packaging is opened, the bugs are once again dangerous."
Mendonca has developed a detection system to uncloak heat-injured Listeria monocytogenes. His system creates an oxygen-free zone that allows convalescing microbes to repair themselves. Now he is working with researchers at the USDA's National Animal Disease Center on a Food Safety Consortium stuty of molecular-based detection methods to more rapidly detect injured Listeria in heat-processed pork and turkey products. Those products include pre-cooked, ready-to-eat meats.
In another consortium project, he's studying added ingredients in pork products. Some additives, such as salt, sodium lactate and phosphate, have antimicrobial activity. The work may help predict more effective combinations of ingredients and heating temperatures to eliminate pathogens.
Mendonca also continues work he began at North Carolina A&T on testing food-grade solutions to destroy pathogens on the skins of cantaloupes and apples.

"We need to be vigilant for emerging foodborne pathogens because of changes in the way we process, package and handle food," he says. "Those changes are in response to consumers' demands for convenience, taste and flavor, extended shelf-life and safety.
"It's also becoming more challenging to develop new ways to protect food because consumers want fewer chemicals and may prefer minimally processed foods," Mendonca says. "Whatever we come up with must maintain food's desirable characteristics. Microbiologically safe food has got to look good and taste good. Consumers look for those attributes first."

Papers and Presentations

John Marcy, Arkansas, delivered several presentations during the spring. In March he spoke on "In Search of Risk-Free Food" to the Mid-Continent Association of Food and Drug Officials in Springdale, Ark., and on food irradiation to the Western Arkansas Dietetics Association in Fort Smith. In April, he spoke on "U.S. Poultry and Egg Food Safety: Where Are We Going" and on "Fecal Contamination: Ways to Reduce It on the Farm" to the Pennsylvania Poultry Sales and Service Conference in Grantville, Pa.
Marcy was program chairman for the Conference for Food Protection pre-conference symposium on bioterrorism conducted in April in Milwaukee by the Federal Bureau of Investigation, the Centers for Disease Control and the DuPage County (Ill.) Health Department. Marcy also delivered a presentation at the Science and Technology Council of the Milwaukee conference.
Evelyn A. Dean-Nystrom, National Animal Disease Center; Harley W. Moon, Iowa State; J. Pohlenz and A. D. O'Brien published "Escherichia coli O157:H7 Causes More Severe Systemic Disease in Suckling Piglets Than in Colostrum-Deprived Neonatal Piglets" in Infections and Immunology, 68 (4).
Laurian Unneveher, University of Illinois, and Helen Jensen, Iowa State, published "Economic Implications of Using HACCP as a Food Safety Regulatory Standard" in Food Policy, 24 (6, December 1999): 625-635.
Food Safety Consortium personnel at Kansas State recently participated in the Excellence in Food Science Day at the university. Daniel Y.C. Fung coordinated the event. Curtis Kastner spoke on "Food/Meat Safety and Research Needs." James Marsden presented the seminar on "Food Safety and Government Regulations."
Curtis Kastner, Kansas State, delivered a presentation on "Technology/Product Development and Safety Issues" in March at the Medicine Lodge, Kan., Extension Program. He was also interviewed by the Topeka (Kan.) Capital-Journal for an article on beef safety research at Kansas State.
Kelly J. Karr-Getty, Randall Phebus, James Marsden, J.R. Schwenke and Curtis Kastner, Kansas State, published "Control of Escherichia coli O157:H7 in Large (115 mm) and Intermediate (90 mm) Diameter Lebanon-Style Bologna" in the Journal of Food Science, 64 (6).
Jim Marsden, Randall Phebus, Elizabeth Boyle, Melvin Hunt, Curtis Kastner and Daniel Y.C. Fung, Kansas State, received a $39,435 grant from the National Pork Producers Council for a project on "Salmonella Risk Assessment for Blade Tenderized, Immersion Marinated, Needle Injected and Fibrinogen Processed Pork Cuts During Processing, Storage and Cooking."
Randall Phebus, Kansas State, received a $24,000 grant from the Kansas Department of Commerce and Housing for a study on "Steam Pasteurization Assessment and Microbial Analysis." Phebus also received a $20,001 grant from the Defense Department to examine "Reactive Nanoparticles as Destructive Absorbents for Biological and Chemical Decontamination" and a $40,000 grant from MAFMA for "Escherichia coli O157:H7 Risk Assessment for Production and Cooking of Blade Tenderized and Fibrinogen Process Beef Steaks."

Food Safety Digest
By Dave Edmark
Hazard Analysis and Critical Control Points systems are now in effect at all of the nation's meat and poultry processing plants with the end of a three-year phase-in of the program in January. HACCP as a matter of national policy has been evolving since the U.S. Department of Agriculture announced four years ago the implementation of the new regulations mandating the system.
Now the government is moving into a fine-tuning phase. Catherine Woteki, USDA undersecretary for food safety, said in a speech in March that the agency was developing intensive methods to evaluate HACCP compliance in plants. These methods would be used by multidisciplinary teams or individual inspectors with extensive expertise in HACCP.
Woteki also announced that the USDA Food Safety and Inspection Service would conduct a survey of about 30 plants that produce ready-to-eat products. The survey's purpose is to determine what actions plants have taken to reassess their HACCP plans with regard to controlling Listeria.
Woteki noted that FSIS is also testing a new plan to extend HACCP procedures to certain activities before and after slaughter that are not currently covered by HACCP. "Plants will be responsible for preventing meat and poultry that are unsafe or unwholesome from entering the food supply," she said. "The new system is now being tested in a number of plants and we will soon have the date that will tell us whether the new system is effective."
* * *
The Centers for Disease Control released its latest estimates of foodborne disease incidence in the nation and concluded that as of last fall about 76 million illnesses a year resulted. That number includes 325,000 hospitalizations and 5,000 deaths. Of the estimated number of deaths, 1,500 of them are said to be caused by three pathogens: Salmonella, Listeria and Toxoplasma.
The CDC said the new estimates are from several sources, including new surveillance systems. CDC Director Jeffrey Koplan said the new estimates should not be compared to previous estimates because the recent figures result from better information and new analyses rather than any change in frequency of diseases.
The report can be found on the CDC web site at

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