For years, the beef industry and the U.S. government have battled E. coli O 157:H7 — the most insidious among pathogens causing foodborne illnesses, to say nothing of its major threat to the viability of ground beef. This seems a Sisyphean effort given the spate of recalls in 2007, especially the one ultimately forcing Elizabeth, N.J.-based Topps Meat Company LLC, the largest U.S. manufacturer of frozen hamburger, to go out of business. Despite all that has been done to thwart this lethal pathogen since the Jack in the Box outbreak in 1992, the watershed event that placed regulatory and consumer focus on E. coli O157:H7 — cases involving contaminated ground beef continue to plague the marketplace.

This report reviews the scientific nature of E. coli O157: H7 in ground beef along with beef-industry production procedures and best-practice pursuits by select grinders.

In his book, “Evolution of Escherichia coli O157: H7 and other Shiga toxin-producing E. coli strains,” Thomas S. Whittam links the emergence of the deadly pathogen to a 1982 outbreak of infectious disease. He writes that the abrupt appearance of E. coli O157:H7 that year — tied to two outbreaks of severe bloody diarrheal syndrome in Oregon and Michigan linked to the consumption hamburgers — raised questions as to whether this organism had recently emerged as a pathogen or had always been present and had simply not been recognized. Seeking answers, researchers associated with national laboratories in the United States, Canada and the United Kingdom reviewed their records and their collections of E. coli samples. They found archived E. coli O157: H7 strains recovered from the stools of patients in those countries.

Escherichia coli O157:H7 is now a major cause of large-scale epidemics and thousands of sporadic cases of gastrointestinal illnesses in North America, Europe and Japan.

“A critical element in the emergence of this foodborne pathogen was the evolution of acid resistance, an attribute that promotes survival in acidic foods and results in efficient transmission with a low-ineffective dose,” Whittam writes.

To be sure, identifying this relatively new pathogen is an essential first step in finding ways to prevent its harmful impact on human health and the beef products it victimizes. The meat industry, the government and the scientific community are looked to for solutions and remedies. Over the years, scientists and industry manufacturers have pointed to the benefits of various substances and systems including organic acid washes, chlorine dioxide, hot-fat trimming, pathogen detection, steam pasteurization, electron pasteurization, food-grade trisodium phosphate, rapid sanitation control and automated hand-washing among many other. Although much has been done, much more needs to be done, which is not lost on all concerned. “Measures to prevent E. coli O157H:7 include lactic acid or acetic acid washes incorporated into specific steps of the process, such as the last step on the harvest floor, or the last step in grinding before packaging,” confirms Shane Dorrian, supervisor, Meat Science Lab, Animal Science Department, University of California, Davis campus. “These preventative measures have been expensive for the beef industry, but have proven to prevent or reduce contamination. The downside is the cost and the change this has on the flavor of the meat.”

Regulations to control E. coli O157:H7 went into full gear in May of 1993, when then Secretary of Agriculture Mike Espy instructed USDA’s Food Safety and Inspection Service (FSIS) to begin the rulemaking process requiring meat and poultry establishments to develop and maintain a HACCP (hazard analysis critical control point) system. The concept was developed in the 1960s by the Pillsbury Co., while working with NASA (The National Aeronautics and Space Administration) and the U.S. Army to produce a food that could be used under zero gravity conditions by astronauts. The goal involved reaching as close as possible to 100-percent assurance that space-program food be free of bacterial or viral pathogen contamination, among other things.

By 1994, E. coli O157:H7 was declared an adulterant. That same year, FSIS mandated safe-handling labels for raw meat and instituted testing requirements.

A spike in recalls and illnesses blamed on E. coli O157:H7 in 2007, prompted FSIS to adopt new policies to minimize risks associated with the pathogen, including expanded ground-beef pathogen detection testing by more than 75 percent. A more sensitive test for detecting E. coli O157:H7 became available in 2008, which reportedly would likely turn up more positive results than in previous years.

Based on the new policies, when ground beef tests positive for E. coli O157:H7, plants will be under increased scrutiny by FSIS for 120 days thereafter: 16 samples for production rates of 1,000 pounds or more per day and eight for fewer that 1,000 pounds daily. This approach aims to rule out problems in plant processes. FSIS also began operating under new test-and-sample guidelines by changing its selection of plants to sample based on history, volume and past positive samples. Federal inspectors takes 50-60 samples per year from production sites to test for E. coli and Salmonella under HACCP.

The essential critical control points in a grinding operation involve the slaughter process and online production.

This phase begins with USDA inspectors’ observation of animals to determine if they are fit for slaughter. Fit animals are stunned by a captive bolt and bled. The removal of various parts follows this step. The carcass is eviscerated after the hide is removed completely. The animal is split down the spine, the spinal cord is removed and the carcass is washed and inspected. Carcasses are coated with an acetic acid spray as a final step.

“This step was only recently enforced by the USDA and FSIS due to recalls of beef contaminated with O157:H7,” Dorrian reports.

The stunning and bleeding process must be executed perfectly, he emphasizes, as the USDA inspector is empowered to file a non-compliance citation concerning the animal handling/humane slaughter step otherwise. Moreover, hides must also be removed perfectly, leaving behind no residual hair or fecal matter.

“The carcass will not move down the line until the inspector OKs the post-hide removal critical control point,” Dorrian reports.

Carcasses should chill a minimum of 24 hours in a high-air-velocity cooler at 38°F. The first essential step concerning plants that receive raw materials such as beef trimmings from other providers is to ensure that the temperature of the incoming material is below 45°F.

Any product received that is found to exceed this temperature shall be considered to possibly harbor bacteria, and must not be used, confirms Dorrian, adding that individual plants employ different standards for receiving materials, but the most common approach is to check the temperature and ensure that all vacuum-packed materials are still sealed.

Often the chuck, between the shoulder-blade and the neck, is used for stew meat or trimmings for ground beef. As Dorrian notes, however, any part of the carcass can be boned out to make ground beef. Jack in the Box Inc. uses the sirloin for its ground beef, for example.

A recent innovation in ground beef calls for using better wholesale cuts of beef, such as ground sirloin, Dorrian notes. “This simply enhances flavor and tenderness,” he adds. “Texture is very important for flavor and tenderness. A finer grind will be more palatable, but some processors have chosen to use a coarse grind to preserve the beef flavor and increase texture.”

Metal detection is essential technology for grinders. Metal detectors, capable of removing foreign metal objects to prevent them from hitting the grinder or knife, are built into grinding systems. “That’s the utopia,” surmises Byron Williams of Alabama A&M University. “There are even devices that can be attached to grinders to remove bone or other contaminants. Inevitably small pieces of bone make it into the grinders. The name of the game is to remove as much contamination before getting into the grinder. Many facilities even have metal detection systems downstream post-packaging to ensure the integrity of the ground beef.”

Trevor Caviness, Caviness Beef Packing Ltd., Hereford, Texas, says necessary plant floor equipment for ground beef production includes a combo dumper, product inspection belt, first grinder, augers that take boneless beef to blender, augers taking product from blender to second grinder, auger going to pump, final packaging equipment, blender, second grinder and pump.

The grinding process starts with beef trim-meat as the raw material that is blended with leaner and/or fatter meats to achieve the desired outcome of fat.

U.S. fed-cattle facilities in the Wichita, Kan.-based Cargill Meat Solutions’ production program use trim from in-house production lines. “We also have a cold-chain management system in place to keep trimmings and finished ground beef product cold throughout the production process,” reports Ivan Brown, the company’s brand manager for ground beef. “Another part of our process is ensuring that all of our grinders and packaging equipment is kept clean and operating correctly. And we routinely perform lean-point accuracy checks. Another step to producing great ground beef, whether that’s case-ready chubs or lid stock trays, is to keep the product moving throughout the production line and into final refrigeration.”

Ground beef is typically made up of 30-percent fat trim, a USDA restriction. The majority of ground beef comprises less than 30-percent fat, typically around 22 percent plus or minus. Categories labeled as ground chuck or ground round contain 15-percent, 10-percent or 5-percent lean meat. Processors grinding various raw materials achieve this blend. Most ground beef is ground twice, typically through a coarse plate initially then through a smaller ground plate of 1/8 of an inch. Some blends go through the grinder a single time depending on the desired texture.

“Food safety is a different ball game and on everyone’s radar screen due to E. coli,” confirms John Marchello, Ph.D, University of Arizona in Tucson. “It is such an issue with all of the recalls that processors are sitting on pins and needles and trying to ensure integrity of ingredients before grinding. They can’t check every ounce of product going in because it is physically and economicallyimpossible. Bacterium is on the surface so when you grind or tenderize it [meat], you carry bacteria internally and spread them.”

trimmings before the grinding step to prevent E. coli is essential. “The friction of grinding causes heat increases in the product,” he explains. “That promotes bacterial action, one of the things we must guard against. Many big grinders grind frozen product to avoid heat from friction.”

Food-safety and related issues head the list of challenges confronting beef-industry grinders in these times of high recalls and other business operating pressures. Even so, the industry continues to pursue marketplace opportunities and employ good manufacturing practices. Key issues involve equipment essentials, packaging technology and adhering to a best-practices paradigm.

“Packaging innovations, product development and equipment updates are all important in producing quality ground beef products,” confirms Brown, of Cargill Meat Solutions. “Cargill collaborates with its customers to determine which packaging solution is the best. Each packaging option serves its own purpose, and that’s why we provide so many different packaging solutions. Some customers prefer case-ready packages. One benefit to this option is that it reduces in-store labor for stocking the shelves. But another customer may prefer to grind and package their own ground beef, so we supply them with large 10-pound chubs.”

The company’s beef packaging solutions include tray overwrap, case-ready lid stock, case-ready chubs, and large chubs for in-store packaging. The company also offers a full range of lean points, like traditional 73/27, 85/15 or very lean 93/7 ground beef. In addition, Cargill can provide customers with specific source grinds, preformed patties, as well as fresh or frozen ground beef.

MAP (modified atmosphere packaging) is the latest technology used in meat applications and is considered the most effective tool in preserving, meat, flavor and texture. Both MAP and vacuum packing act to reduce oxygen in the meat environment. MAP removes oxygen but replaces it with carbon dioxide/nitrogen. The air is taken out of vacuum packaging. “Both are effective at reducing oxidation of the meat and preventing freezer burn,” Dorrian explains. “Vacuum packing reduces the texture of the meat due to the nature of air removal, which compresses the product. MAP does not have this effect.”

Concerning food safety, Brown says Cargill uses a multi-hurdle approach in its fed-cattle plants, including hide-on carcass wash, steam vacuum process, organic rinses and steam pasteurization, among other hurdles. “Another important safety intervention is the use of metal detectors, and regular quality-control checks to make sure they are working properly,” he adds.

Holding product while test results are pending is considered a good business practice. Test-and-hold procedures for finished product should be used to determine product safety, advises the International HACCP Alliance. Effective practices for identifying and holding products should be used when the establishment conducts the test and FSIS or another government agency takes a sample.

By Timothy P. Biela, Chief Food Safety & Quality Officer

American Foodservice Corp. and its affiliated companies including Texas American Foodservice Corp., American Fresh Foods, Fairbank Farms and F. W. Foods LP rank among America’s largest and established regional suppliers of the beef patties and ground beef products for foodservice and retail customers. Approximately 60 percent of production is beef patties for the Burger King Restaurant chain; 15 percent for Jack in the Box Corp. The balance of production is related to producing patties for various institutional food service suppliers, commercial fast food, casual dining and retail groceries.

American Foodservice produces approximately 350 million pounds of beef patties and ground beef products per year at four processing facilities. The first in King of Prussia, Pa., supplies beef patties to a territory east of the Mississippi. The other processing facilities are located in Fort Worth, Texas, Ashville, N.Y. and Thomasville, Ga. The facilities in Texas (Texas American Foodservice and American Fresh Foods) produce beef patties and retail ground beef products for the central south, western and southwestern sections of the United States. The Thomasville, Ga., facility produces frozen ground beef patties and retail ground beef for the southeastern U.S, and retail ground beef for the northeastern U.S. is produced in Ashville, N. Y.

The production process is basically identical in each processing facility and starts at the loading dock where all meat is inspected for “character” and conditions of transportation are verified. If the raw materials are fresh, free of any odor or color and received within the strict guidelines as set forth by American Foodservice Raw Material Specifications (which are more stringent than the USDA) with respect to the age, microbiological quality, temperature, fat content and many other parameters, then the raw material is accepted. The company produces finished product from fresh and frozen boneless beef purchased from federally-inspected raw material suppliers. All incoming raw materials are required to be sampled and tested specifically for E. coli O157: H7 prior to receipt.

Once the fresh and frozen boneless beef is accepted, it is moved from the refrigerated dock area and stored in either a freezer and held at 0ºF, or in a cooler held at less than 40ºF.

The actual production of the ground beef begins with 60-pound blocks of frozen meat passing through a tempering tunnel to bring the temperature up to a workable range of approximately 26ºF. Frozen blocks then enter a “coarse grinder” to reduce the blocks to beef chunks about 2.5 inches in size. The ground raw material is deposited in movable, stainless steel or plastic bins. The chunks along with similar bins of fresh, lean beef go in another coarse grinder that grinds the two types of beef together, producing combined beef chunks sized at roughly 3/8 of an inch.

Corn-fed beef is added to the combined mixture to achieve the “unique” beef flavor. Screw conveyors move these two types of beef to separate blenders where they are blended together at a high rate of speed to produce a blend with a “uniform fat content.” This process yields a 3, 000-pound batch of “beginning” raw ground material that is sampled and the fat of the blended material verified. This step is taken to verify that the ground product has been produced in accordance with customer specifications.

The next steps include a final grinding process whereby the product passes through a grind plate that automatically extracts bone and gristle or other hard materials remaining in the blend. All ground-beef processing lines are equipped with the most sensitive metal detectors available and the operation of these detectors is constantly verified by the plant quality control staff. Final blended material is hydraulically dumped into patty forming machines to produce frozen or fresh patties or in mechanical stuffers to form loaves or chubs. A patty forming machine creates frozen patties by gently forming the meat at about 30 ºF. The finished patties are immediately perforated and transferred into nitrogen or mechanical tunnels to be frozen solid to less than 10 ºF. For chubs, ground beef flows from the grinding system in the chub machine to be sealed into plastic film specifically designed to protect the ground product until it reaches its distribution destination. Finished product is stored in on-site freezers or coolers for roughly two to five days.

In addition to USDA officials, an in-house quality control team continually monitors the production process and defined controls, which not only includes a visual inspection to watch for unwanted foreign and indigenous materials, but also involves performing tests on the fat content as well as conducting random sampling of the in-process materials for attributes and bacterial analysis.

All aspects of the operation are outlined in the company’s Operations Manual along with detailed written Standard Operating Procedures composed by company owners and the executive staff. They are reviewed and updated annually, unless more frequent updates are necessitated by changes in the process, regulatory changes or other changes in the industry.

• In a strictly-regulated, USDA-inspected facility, customers and/or visitors should not enter production areas without proper clearance.

• To ensure that no foreign materials end up in beef patties, all visitors to the plant must also wear frocks and hairnets.

• Maintain details files on each supplier providing raw materials and/or services to be maintained by the Quality Control Directors in all of the facilities, an important step in keeping a “track record” for resolving problems that may exist or may be attributable to a particular supplier. Further, keep a list of any rejected beef and any foreign materials discovered during the production process.

• Raw materials are only received from a select group of long-term suppliers. Despite long, established relationships with beef suppliers, the right to reject any load of beef suspected as unwholesome or does not meet high “character levels” set forth applies.

• Maintain the plant at a constant 50 ºF to eliminate potential for bacterial growth.

• All production equipment is constructed with USDA-approved stainless steel or plastic.

• A full-time sanitation staff thoroughly cleans all equipment on a daily basis with high pressure hot water. All employees are familiar with the equipment enabling them to perform preventive maintenance when necessary.

• All food handlers in processing facilities must wear clean rubber gloves, white frocks or coveralls and hairnets.

• To prevent foreign objects from entering beef patties, all meat passes through a bone/gristle elimination system.

• No exposed glass is allowed in processing areas based on USDA regulations, therefore all light fixtures are double shielded and bulbs are shatter proof to prevent any potential for glass in products.

• Every ground beef product passes through a metal detector at the end of the production process. The metal detectors are tested each hour during the production shift to make sure that they are working properly.

• Each meat patty is frozen to less than 10ºF the instant it leaves the hamburger forming machine making it impossible for any foreign objects to become embedded in the finished product. All retail and foodservice ground beef is “sealed” during the process to prevent the intrusion of foreign objects post-production.

• The production and shipping areas are kept in a clean sanitary condition at all times. Eating and smoking are strictly prohibited in plant areas.

• Finished goods are immediately sealed with tamper evident transparent tape after they are packed in a shipping container. This eliminates the possibility of foreign objects entering the box during shipping.

• Employees involved in the production process are trained to constantly watch for foreign objects.

A study examining the effect of dust cloud exposure during load-out at feedlots found that the prevalence of both Salmonella and E. coli O157:H7 on cattle hides was greater after exposure. A controlled study found that cattle loaded on a clean, concrete surface had fewer-percent positives than cattle loaded in a dirty, dusty facility.

A study examining sampling methods found E.coli O157: H7 more likely to be recovered from fecal grad samples than rectal and swab samples. If researchers had just used fecal grab samples, 45 percent and 50 percent of the animals positive for E. coli O157:H7 and Salmonella, respectively, would have been missed. The sampling location is a critical criterion to consider in the future.

A post-harvest research project investigated the use of lactic-acid cultures and their ability to reduce E.coli O157:H7 in fresh meat, poultry and ready-to-eat meat products. The product haven approved for use as a surface application and petition has beensubmitted to USDA to remove label requirements.

Texas Tech researchers have also investigated packaging systems and their effect on Salmonella and E.coli O157:H7, as well as the ability of low oxygen, high oxygen packaging and rosemary extracts to reduce spoilage in ground beef patties. This research indicated that modified atmosphere packaging (MAP) decreased pathogens and also inhibited non-pathogenic organisms that can lead to spoilage.