Food Safety Nation

Killer spinach. Dangerous peanut butter. Poison pet food. Toxic canned beans. Risky pot pies. In the wake of such events, it’s no wonder that the latest “U.S. Grocery Shopper Trends” survey from Food Marketing Institute (FMI), Arlington, VA, shows consumer confidence in food safety at an all-time low. From 1996 to 2006, 82% of consumers reported they were “completely” or “mostly” confident about food safety. In 2007—one year later—that number dropped nearly 20 percentage points to 66%.

Clearly, new approaches to help ensure the safety of our foods were necessary.

The first move was to push for a federal regulation requiring pasteurization of nearly all almonds grown in the United States, which is now a reality (effective Sept. 1 2007). The second part of ABC’s plan, a research campaign to develop and advance food-safety technologies, was “one of the most significant collective decisions that we made as an industry,” says Richard Waycott, CEO and president, ABC.

ABC set up an independent technical expert review panel to evaluate the efficacy of existing and emerging technologies to achieve a minimum 4-log microbial reduction without adversely impacting almond quality. Accepted technologies were submitted by vendors to FDA for agency acceptance, which requires a 5-log pathogen reduction. After three years of review, FDA listed oil roasting, blanching, fumigation with propylene oxide, and steam processing as acceptable treatments. Of the four, steam-based sterilization emerged as the “new” technology.

None of the accepted steam-sterilization companies had used the technology before to pasteurize almonds. David Howe, vice president of operations, Sterilization & Fumigation Services, Inc., Jamestown, RI, which manufactures H2O Express, notes that his company’s background is in the medical-device industry. “We know that applying steam heat at a high enough temperature and the right exposure time will kill pathogens on the surface of a product, whether a medical device or an almond. But with the additional requirement that the treated almonds must retain their rawlike texture, natural flavor and color, we have to adjust the process, reducing the rate of pressure and lowering the temperature of the steam so that it penetrates rapidly and evenly to preserve the desired quality attributes and still eliminate the bacteria that is dangerous for human consumption.”

During ABC’s research, says Howe, other significant advantages came to the fore, including extended shelf life and improved taste. “Also,” he notes, “this technology can be used on organic or conventionally processed almonds.”

Chicago-based FMC FoodTech’s JSP-I Jet Stream Almond Surface Pasteurization System combines superheated steam, short pasteurization times and water membranes to kill bacteria on the almond’s surface. “What’s really exciting about the steam process is that we are finding that we can adjust the system to decontaminate the surfaces of many types of dry foods, including other tree nuts, spices, raisins, herbs, grains and flavorings,” says Jun Weng, Ph.D., research fellow, FMC FoodTech.

COLD PLASMA HEATS UP 

The almond industry’s over $1 million investment in food-safety R&D has renewed interest in other pathogen-reduction treatments. One technique, cold-plasma technology, might also prove a potentially effective treatment for almonds, among other foods.

Also known as atmospheric or nonthermal plasma, the process uses high-voltage electricity to ionize a gas to generate a plasma field. This gaseous energy breaks down the oxygen molecules of the air passing near the electrodes into reactive oxygen species. Bacteria, viruses and spores exposed to the plasma field are eliminated on contact, and the plasma dissipates immediately when the electrode is turned off.

Cold plasma decontaminates the surface of produce without destroying organoleptic attributes, notes Cynthia Stewart, Ph.D., director of scientific affairs, National Center for Food Safety and Technology (NCFST), Illinois Institute of Technology, Summit Argo, IL. “Although food scientists have been looking for years at the effectiveness of cold plasma in foods, the almond industry’s call for solutions has proved a catalyst for universities and research institutions to renew technology research and development efforts in this area,” she says. “It is a very promising technology, particularly as we look at how to make dry food ingredients safer, such as raw nuts, spices, powders and infant formula.” She notes that the technology is currently limited to surface decontamination treatments.

Because nonthermal plasma holds such promise, NCFST recently partnered with Enercon Industries Corporation, Menomonee Falls, WI, to test the efficacy of its atmospheric plasma system for pasteurizing raw almonds. Rory Wolf, vice president of business development, Enercon, says the company will develop prototype atmospheric plasma equipment for the project based on its existing system, which has been highly effective in sterilizing nonfood items like medical devices and garments. “Unlike the huge vacuum chambers associated with plasma technology in the past, we have created an in-line, conveyor application—essentially a discharge electrode assembly that is focused over a surface—that has the potential to be ideally suited for a food-production environment,” he says, noting that “since the byproducts of the process are all basically inert, we do not expect any organoleptic issues to arise.”

In Aug. 2006, Intralytix, Inc., Baltimore, kicked open the door for rapid, real-world application of the technology as a processing aid when its bacteriophage-based preparation, LMP- 102™, became the first to receive FDA approval as a food additive. Comprised of six individually purified, Listeria-specific phages, the preparation is sprayed onto the surface of ready-to-eat (RTE) meat and poultry products, eradicating 170 strains of the pathogenic contaminant. The six-phage formulation is designed to reduce the pathogen’s ability to develop resistance to the treatment. The company is currently developing a similar phage to reduce E. coli O157:H7 contamination on produce and ground beef.

Listex™ bacteriophage, from EBI Food Safety, Wageningen, the Netherlands, also targets L. monocytogenes in a variety of RTE products. It has attained GRAS status, USDA acceptance and European Union approval for use as a processing aid in the production of organic food.

Bacteriophages are also weaving their way into routine testing. Two phage-based screening tests have received Performance Tested Method status from AOAC International, Gaithersburg, MD: Premi®Test Salmonella, manufactured by DSM Nutritional Products, Geleen, the Netherlands, in collaboration with Check- Points BV, Wageningen, the Netherlands; and the Profos Listeria Capture Kit, developed by Profos AG, Regensburg, Germany.

Although concerns about food safety might be at an all-time high, technology is advancing in step to help reinstate peace of mind. Sometimes, it’s just a matter of using the right tools for the job.

Julie Larson Bricher is editorial director of Food Safety Magazine, a trade publication providing information on science-based solutions for food-safety and quality-assurance professionals. A professional journalist and editor for 19 years, she is a member of the International Association of Food Protection and the American Society of Business Publication Editors.