The National Provisioner | Food Safety News

Work Continues on Antimicrobial Solutions for Food Safety

The National Provisioner — Mon, 31 Mar 2014 05:01:50 +0000

Antimicrobial solutions are used to reduce contaminants on raw foods such as meats, vegetables and fruits. This is analogous to washing food prior to using it in one’s own kitchen, although these compounds enhance the washing action, says Martha Ewing, director of technical services at Sanderson Farms Inc. of Laurel, MS. Antimicrobial solutions have proven to be very good at treating certain contaminants on animal carcasses and on primal and subprimal cuts, says Jim Dickson, professor in the Department of Animal Science, Inter-Departmental Program in Microbiology at Iowa State University in Ames. “It’s one of the more significant introductions … in meat and poultry in the last 25 years,” he says. The statistics support that fact as well: Antimicrobial solutions are working. According to U.S. Department of Agriculture data for poultry, the Salmonella incidence rate has been reduced 26 percent from the beginning of 2013 and 55 percent compared to five years ago. Further, data indicate that the number expressed as a Most Probable Number of Salmonella is very low – fewer than 10 microorganisms when a positive result is enumerated, Ewing says. One of the biggest challenges for processors of ready-to-eat (RTE) products that are exposed to the environment at packaging is the potential for Listeria monocytogenes contamination, explains Lynn Knipe, extension processed meats specialist and associate professor in Food Science and Technology, and Animal Sciences at Ohio State University in Columbus. “For intact fresh cuts and for ready-to-eat products, surface contamination has been the greatest concern for processors, and I don’t see that changing in the near future,” Knipe says. “Since this is a surface contamination, sprays and dips can have the greatest impact on the surface contamination.” Gaining ground Newer compounds and application strategies are being developed for antimicrobial solutions. Lauric arginate, for example, was introduced in the United States a few years ago as an effective antimicrobial spray against Listeria. “Lauric arginate may be sprayed directly on to RTE meat products prior to packaging, or sprayed inside the pouch before the meat product is inserted into the package,” Knipe says. “The latter option relies on the vacuum to distribute the lauric arginate uniformly around the packaged product. More recently, it has been shown to be effective as a surface treatment to eliminate Salmonella on chicken.” Peroxyacetic acid is a new chemical that’s been widely used, especially in the beef industry, Dickson says. In the poultry industry, carcass washers apply sprays to both the inside and outside of the body cavity, as well as to the external surfaces, he says. One of the newest advancements in some poultry plants has been the use of a wash after the carcasses come out of the chiller. “If you spray an organic acid on a poultry carcass and then you put it into a chiller, then it pretty much washes all of that off,” Dickson says. “There have been some that are using a wash or spray cabinet after carcasses come out of the chiller, and that seems to be pretty effective.” The compounds commonly used today are considered processing aides and do not have a residual effect. If a residual effect was present, the compound would be considered an ingredient and would have to be included on the label. Nevertheless, some clean-label products, which involve vinegar and lime juice, have been developed that are effective in eliminating surface contamination of both Listeria monocytogenes and Clostridium perfringens on RTE meat products, Knipe says. “With the consumer pressure for clean labels, these products provide the product safety needed [for processors and consumers], without chemical names that concern consumers,” he says. Additionally, much work is being done in spices, botanicals, phyto-antimicrobials and phyto-chemicals to see if compounds can be isolated from various plants and/or seeds to have great antimicrobial effects, says Robert Gravani, a professor of food science in the Department of Food Science at Cornell University in Ithaca, NY. “Certainly one of the areas that is being actively researched is the synergies that may develop between antimicrobials that are used in concert with each other,” he says. Research also needs to continue on antimicrobials to make sure they are still effective against the organisms to which they are targeted, he adds. “Clearly one of the things in people’s minds is, ‘Will there be new compounds coming in the future that will be even more efficacious than what we have now?’” Gravani says. “We’ve got to be constantly prospecting toward new compounds that will work that are as effective or more effective than the ones we have today.” In addition, Ewing says, multiple points in each process are being evaluated for application effectiveness. “The majority of these revolve around a water-based application, but other technologies are also being evaluated, such as UV light and high-pressure pasteurization,” she says. Antimicrobial solutions are being applied in more points during processing as well. For example, when organic acids first came out for beef carcass washes, they were only applied at the end of the process after the final carcass wash, Dickson says. Then some companies started applying them pre-evisceration, which is now pretty standard in the industry, he says. Now, companies are spraying carcasses when they come out of the coolers. “In some cases, they are getting treated as many as three times with some of these antimicrobial solutions,” Dickson says. “It’s all with the idea of reducing the potential of contamination on the surface of the animal.” However, the cost of some of these antimicrobial products may be keeping some processors from using them on their products, Knipe adds. Still, the industry continues to look for new compounds and methods of antimicrobial wash application. As technology improves, so will the ability of these compounds to reduce microbial contamination. However, Ewing reminds that, while antimicrobial compounds can help reduce the level of microbes to almost undetectable levels, the product is not sterile. Safe food-handling techniques must be employed at all times when handling raw food. (“Work Continues on Antimicrobial Solutions” by Elizabeth Fuhrman first appeared in The National Provisioner on December 6, 2013. Courtesy of The National Provisioner.)

Biosecurity Plans: Defending the Food Supply

The National Provisioner — Mon, 17 Mar 2014 05:03:07 +0000

If a disease outbreak occurs in today’s interconnected global economy, the stakes are higher than usual: Expect lost domestic and international sales, a damaged reputation, and even a hit to the U.S. economy from lost trade and employment. The desired outcome, of course, is to prevent disease outbreaks with strong biosecurity plans. Are today’s plans up to the challenge? U.S. Poultry & Egg Association (USPOULTRY) recently updated its “Infectious Disease Risk Management: Practical Biosecurity Resources for Commercial Poultry Producers” program with the guidance of industry and academia members. The program was created to aid in developing more effective biosecurity practices, and it is designed to be used as a multi-purpose, reference, employee training and teaching tool. Revisions were made to the dead-bird disposal and pest-control management sections, and the resource section includes signs and forms for meetings and monitoring. “Existing biosecurity programs at the farm and the processing plant provide a strong foundation for an effective food-defense program,” says Rafael Rivera, manager, food safety and production programs, USPOULTRY. “There is always room for improvement as we implement training tools that help both salaried and hourly employees understand their roles in protecting the food supply.” The National Turkey Federation (NTF) and the American Meat Institute (AMI) released a video presentation last fall of a turkey farm and processing plant. The video, hosted by leading animal-welfare expert Temple Grandin, Ph.D., professor of animal science at Colorado State University, continues efforts to increase the transparency of meat and poultry processing, and show a humane, safe and efficient operation. According to the U.S. Department of Agriculture (USDA), there are six main steps to follow to prevent poultry disease:

Keep your distance: Restrict access to your property and birds at all times, and fence off the clean and dirty areas from each other. In addition, farmers should only allow their bird caretakers to come in contact with the birds.
Keep it clean: Don’t bring your germs into the birds’ area by wearing dirty shoes and clothes and by not washing your hands before entering. Also, keep the birds’ living conditions clean by providing clean food and water, removing manure and dead birds, and disinfecting their cages and any equipment that touches their droppings.
Don’t bring disease home: Your car, tires, cages and equipment can transport germs from areas where other birds are present. Also, keep new birds separated from the flock for 30 days (because they may have a new disease), and never mix species or birds from different sources.
Don’t borrow disease from your neighbor: In this case, fences make good neighbors. If you are borrowing equipment from another bird owner, disinfect it before introducing it to your birds. However, wooden pallets and cardboard egg cartons are never acceptable to share because their porous surface makes them impossible to adequately clean.
Know the warning signs of infectious bird disease: Early detection is crucial to prevent the spread of disease, but it can be hard to spot. Poultry owners should look for sudden death; diarrhea; decreased or loss of egg production or soft-shelled, misshapen eggs; sneezing, gasping for air, nasal discharge and coughing; lack of energy and appetite; swelling of tissues around the eyes and in the neck; purple discoloration of the wattles, combs and legs; and depression, muscular tremors, drooping wings, twisting of head and neck, incoordination and complete paralysis.
Report sick birds: Call your agricultural extension agent, local veterinarian, the state veterinarian, or USDA Veterinary Services office. USDA will test sick birds for free and conduct a disease investigation so processors can find out if they have any serious diseases in their flock.

The definition of biosecurity has evolved since 9/11. Food defense and agro-terrorism have certainly received more attention, and the U.S. Food & Drug Administration (FDA) has published voluntary guidelines and food-defense plans for processors, says Rivera. “Our members and their customers understand the importance of food-defense programs, and information concerning food-defense plans is beginning to appear as part of many food-safety audits,” he says. “As noted above, biosecurity at the farm has taken on additional meaning as a way not only to prevent disease in animals, but also as a valuable part of a food-defense plan.” It is expected that the poultry industry, working with FDA and USDA’s Food Safety and Inspection Service (FSIS), will continue evaluating its food-defense programs and develop new training programs. “With more food products being imported, the government’s role in addressing food defense at the port will increase,” Rivera says. “Food defense will be considered as a process that needs to be handled from farm to fork just like what we do with food safety programs.” Keeping calves healthy Strict biosecurity plans are essential to beef cow-calf operations as well. According to Michigan State University Extension, here are steps that will minimize introducing new diseases to the farm:

Develop biosecurity plans with the consultation and advice of a veterinarian.
Understand your farm’s greatest risks. Newborn calves, for one, are the most vulnerable to disease because they are born with few immunities.
Isolate potentially infectious animals. Also, fostering new calves with cows who lost their own calf is discouraged as the new calf can introduce new germs.
Traffic control: Pay attention to the flow of oncoming vehicles, animals and people, as new diseases can be introduced and spread quickly through the pens. Farmers should start tending to the healthiest and youngest animals first and the sick animals last.
Sanitation: Visitors and producers need to wear clean clothes and sanitized footwear before visiting livestock operations and sick pens. Also, the livestock trailers and barn environments should be kept clean with manure removal, fresh bedding in the barns and cleaned and disinfected equipment such as feeders and waterers.

“Defending the Food Supply,” by Elizabeth Fuhrman first appeared at The National Provisioner on Jan. 10, 2014. Courtesy of The National Provisioner.

Rethinking Clean-In-Place Design

The National Provisioner — Mon, 03 Mar 2014 06:02:03 +0000

Which comes first: clean-in-place systems or plant design? All too often, it is the plant design that comes first, and then processors have to retrofit — at great cost — their equipment to be clean-in-place (CIP). Although meat and poultry processors aren’t directly affected by the Food Safety Modernization Act’s upcoming regulations on HACCP documentation (due to already following HACCP procedures for 20 years under USDA’s FSIS), it never hurts to reassess the sanitary design of their CIP or open-plant cleaning (OPC) systems. In its most common form, CIP involves the pressure-washing of pipelines or processing equipment, or alternatively, spray-cleaning of transportation tankers and fixed tanks and processing vessels of all types in the production facility, says Dale A. Seiberling, a food industry speaker and former Ohio State University instructor in dairy technology. “Spray-cleaning extends to include the cleaning of large spray dryers, evaporators, bins, cyclone separators and ductwork in those segments of the food-processing industry that use such equipment,” he says. This technology has been applied in a few instances to what might be considered open-plant cleaning. “For example, in the dry cereal industry, more than 30 years ago, one manufacturer wanted to reduce the labor, reduce the time and improve the efficacy of cleaning the dry cereal process,” he says. “The end result is that an area the size of a football field and 100 feet in height, with cereal production equipment arranged on space frames with open floor grating, is wet-washed inside and out in approximately five-and-a-half hours, whenever required.” In recent years, new pumps, valves and chemicals have been created that processors use with their CIP or OPC systems to improve food safety, says Tim Bowser, Ph.D., a food process engineer at Oklahoma State University based in Stillwater, OK. “There have been a lot of innovations, such as surface coating and finishes that are smoother and/or have antimicrobial characteristics or anti-stick [hydrophobic] qualities, variable-speed drives [VSD] for better pump motor control, new sensors for verification of automated CIP procedures, new materials and methods of construction, better integration of controls and wireless technology, and new valves that are easier to clean and maintain,” he says. In particular, Bowser says food safety has been improved with new technologies that include:

Automated controls that make cleaning cycle execution almost flawless,
Automated controls, equipment and sensors that significantly reduce cross-contamination,
New surface finishes and technologies that make parts easier and faster to clean,
Better chemical technology that is more effective on soils, and
Better welding and finishing equipment that makes installations faster and cleaner.

However, the “real need is not for new technology but rather the application of ‘CIP-able’ design to all aspects of the process and the equipment involved,” Seiberling notes. Bowser agrees that one of the biggest challenges for CIP systems is to educate processors about their importance before designing their plants. “People don’t think of CIP when designing their plants, but it should be one of their biggest issues,” says Bowser. He notes that, for example, many plants today have issues with drainage because they tend to only contain one level. “We need to re-think the paradigm of where to locate cleaning processes,” he says. “It’s a huge physical issue because of the way the drainage circulates as a result.” Other remaining challenges that affect CIP are the need to “reduce the cost of installations, especially the costs of operation and cycle time, material-handling issues and improve environmental impact,” Bowser says. In the end, “the application of CIP technology is dependent on the processors’ need and/or desire to clean a processing system to the highest degree achievable by the combination of mechanical action and flow of chemical solutions,” Seiberling says. (Editor’s Note: “Re-thinking CIP design” by Megan Pellegrini originally appeared in the National Provisioner on Sept. 20, 2013. Courtesy of The National Provisioner.)

Advancements in Rapid-Testing Technology

The National Provisioner — Tue, 18 Feb 2014 06:03:40 +0000

The sooner one finds out a food product meets quality and safety requirements, the sooner it can be sold. That is why scientists are working to advance rapid testing, so companies easily can decide what to do with product to prevent foodborne illness. Examining rapid testing in the beef industry today sheds light upon how complex the detection of microorganisms can be. For example, beef processors, who are generating or receiving boneless beef trim to grind into ground beef, are testing every 2,000-pound combo. It’s an enormous and dynamic type of process, explains Randy Phebus, a professor of food safety and defense in the Department of Animal Sciences and Industry at Kansas State University. “Chilled inventory capacity is super-restrained in some of these companies, and it’s also a very perishable product,” he explains. “You just have to be able to release product after a negative screen quickly so that you are not building up such a huge amount of inventory.” Phebus and Rod Moxley, a professor at the School of Veterinary Medicine and Biomedical Sciences at the University of Nebraska-Lincoln, are leaders on a $25-million coordinated agricultural program (CAP) grant from the U.S. Department of Agriculture (USDA), with one of the grant’s primary objectives focused on detection methods for Shiga toxin-producing E. coli (STEC) in the beef industry. USDA’s Food Safety and Inspection Service (FSIS) has specific protocols for its regulatory support laboratories to follow to detect organisms that are extensive. Typically it may take four days or more to complete the entire procedure. The first day involves broth culture, and, on day two, screening tests are done. If these tests yield positive results, it is called a “potential positive,” and the product is held until further testing can be completed. If, upon additional testing, usually on day three, positive results are again obtained, this is called a “presumptive positive.” More laboratory work then is required to isolate the organism and confirm its identity and virulence traits. “Time is extremely important,” Moxley says. “When you have product in the plant that has been screened for these pathogens and has test results that qualify as a potential or presumptive positive — meaning that the test results indicate the pathogen may be present, but more testing is needed — then that product is just setting there, and this creates problems.” In reality, if a company gets a presumptive positive test result, in most cases, they are not holding on to the product for another one or two days of confirmation tests. “They basically send it to cooking operations where, through a validated process, you can kill any potential pathogens by cooking,” Phebus says. “That really is a devaluation of raw materials, so you don’t want to do that if you don’t have to.” Rapid testing advances In general, current rapid-testing developments are being made in two main areas: DNA-based and immunological-based methods. Most DNA-based methods use a technology known as polymerase chain reaction (PCR). PCR detects specific sequences of DNA indicative of target pathogens as, for example, bacteria. PCR has been further improved and developed to include real-time PCR. Real-time PCR is a type of rapid testing that detects relatively quickly a DNA-sequence target and also may provide some data on the quantity of the microorganism, Moxley explains. Real-time PCR test results are possible in an hour and a half, not including upfront sample preparations and sample enrichment. “It has an advantage of being rapid, specific and quantitative to some extent,” he says. Immunologically based testing methods use specific antigen-antibody reactions to screen sample enrichments for a target pathogen and/or test pure culture isolates as part of identification and confirmation steps. CAP grant scientists are in the process of developing monoclonal antibodies against the six STEC serotypes currently defined as adulterants in beef. Most immunologic-based methods used today for E. coli O-antigen detection employ polyclonal antibodies, which are not as specific as monoclonal antibodies. “These would be very specific antibodies against the O group,” Moxley says. An example of an immunologic-based testing system would be lateral flow devices. “Some lateral flow devices have been developed for E. coli O157:H7 a number of years ago that resulted from the development of monoclonal antibodies,” Moxley says. “Now that we would be developing these others, we will try to develop lateral flow devices for these other O groups.” Scientists also involved in the CAP grant are developing other immunologically based methods that will come from the grant’s monoclonal antibody development called a wave guide-based biosensor, a next-generation assay. “This would be a way to detect the proteins that would be present like Shiga toxin in a sample,” Moxley explains. “It would also detect the O group that is on the surface of the bacteria.” One of the advantages to immunological-based diffusion-type assays is that they are lower cost, Phebus says. “You don’t have to have specialized equipment,” he explains. “It’s basically like a home pregnancy test. People, even small companies, can do this very easily, and you don’t have to have all the sophisticated, expensive equipment that PCR might require. There is never a one-size assay that fits all analytical needs. It is dictated by what type of laboratory, what type of technical expertise and what kind of money … you have to buy and utilize these systems.” Problem-solving One of the challenges to rapid testing is having the right equipment, expertise and skilled technicians for doing tests such as PCR. “Some of these different protocols, especially the one that the USDA’s FSIS uses, are designed to be extremely thorough and definitive,” Moxley says. “In doing so, it can be very time-consuming and expensive, and it requires a lot of equipment.” Another of the challenges of rapid testing for E. coli is lack of specificity for the six non-O157 STEC groups. These organisms are not known to have general biochemical characteristics that allow scientists to differentiate them from non-pathogenic E. coli, Moxley says. For example, tests can detect individually the O group, the Shiga toxin genes and an attachment gene, but in a mixed culture like enrichment broth, the tests cannot determine whether those individual genes came from one organism or a combination of organisms. In the latter case, it may be that none of the organisms contributing these genes qualifies as the pathogen, and this is a false positive result. A problem in E. coli screening tests is the generation of false positives, and this is why so many additional steps are done in standard testing to make sure that a determination of a positive result is based on confirmation of the pathogen, Moxley adds. One of the ways scientists have been working on trying to overcome this problem is to simultaneously test for a rather large collection of gene targets that yields a higher degree of specificity, and to do so in a real-time format. For example, if collectively a test could detect the presence of a larger batch of genes, and this test has the ability to detect minor variations in a given gene, then the odds of the test result being something other than the pathogen are significantly decreased, Moxley says. “The technology is out there and being developed by some of our scientists and others outside of our project to do this, so I think that the future will be that we will see the development of DNA methods that are able to be validated and specific,” he says. Another problem mainly with DNA-based rapid testing would be sensitivity issues. In the beef industry, for example, looking for a pathogen in a 2,000-pound combo could be like finding a needle in a haystack, Moxley says. “The sensitivity problem has to deal with low concentrations of organisms in large volumes of meat and contamination that is not uniformly distributed,” he says. Moxley believes the development of new methodologies that are more sensitive and specific are within reach. He also thinks the use of antibody-based methods will play a significant role, especially for processing plants and laboratories that don’t have expensive equipment and expertise to run other kinds of DNA-based methods. “Those antibody-based methods that can detect the proteins or the O antigens are likely to be very useful as effective rapid screens in smaller laboratories,” Moxley says. Another area of interest is handheld devices that could be used in plants. Equipment companies are researching handheld devices for both DNA-based and immunologically based methods. Phebus also believes the industry will continue to see major improvements and research being done in the area of product sampling, target culture amplification and analytical sample clean-up. “These are the bottlenecks or limitations associated with the rapid methods that we currently utilize,” he says. “Automation of the sample acquisition, prep and sample introduction into the assay steps will play a big role in future improvements in commercial-oriented food product testing.” (“Advancements in Rapid-Testing Technology” by Elizabeth Fuhrman first appeared in The National Provisioner on Nov. 11, 2013. Courtesy The National Provisioner.)