The Case for Irradiation

  According to Robert Mahler, lead attorney in the litigation against San Diego-based Jack-in-the-Box following the 1993 E. coli contamination incident, consumers expect industry to take every possible action to protect food safety. Mahler contends that if irradiation had been approved for red meat at the time of the Jack-in-the-Box case, it would have increased the damages sought against the company. Mahler poses this question: As a food supplier, how do you tell a jury comprised of grandparents and parents that you chose not to use irradiation - a process that has 50 years of research behind it and more testing than any other food processing technology in the world; a technology endorsed by major government, scientific and world health organizations that adds only a few cents per pound to the cost of a product? Such a tough question is leading more food companies to actively plan integration of irradiation into their production processes.

  While the public may believe that foodborne illnesses frequently result from unsanitary conditions or pest infestations, these are hardly the only challenges. New and more virulent strains of pathogens continually appear. Salmonella, Campylobacter, E. coli and Listeria are just a few pathogens with which the food industry must regularly contend. Add the challenges of combating pathogens such as Listeria monocytogenes (which thrives in a refrigerated environment - the very same environment that inhibits growth in most other pathogens), and it becomes increasingly clear that conventional control methods are not sufficient.

  In fact, a recent report by the federal government urged pregnant women and the elderly to stop eating soft cheeses, and to cook hot dogs and deli meats thoroughly, to avoid the risk of listeriosis. An outbreak of this microorganism in hot dogs and deli meats in early 1999 claimed 21 lives in the United States, and sickened more than 100, according to the Centers for Disease Control and Prevention, Atlanta.

  Despite a continuing barrage of chemical, microbial and microcidal compounds submitted for USDA approval to combat pathogens, contamination shows up in new places every year. Heightened concern for food safety results not only from the evolution of pathogens, but also from today's global food distribution process, the growth in convenience foods and increased pathogen-detection technology. With the developed world increasingly reliant on restaurants and ready-to-eat (RTE) meals, while simultaneously demanding fewer chemicals, additives or preservatives, processors face a tremendous technology challenge. Proven control measures such as irradiation, which can provide a terminal kill step, are mandatory.

  It's not surprising then that the food industry is pressing both the FDA and Congress to make irradiation more readily available.

  In the United States, a very limited number of items have thus far been approved for the process because of the complex and time-consuming regulatory approval process. The FDA regulates food irradiation in a manner opposite of that for most food-safety processes. Each specific food category requires approval before it can be irradiated. In spite of all the documentation and acceptance of irradiation's safety, processors cannot use irradiation in the same way as other processes, such as canning, cooking, freezing or dehydrating. This leaves food processors, the people with expertise, responsibility and liability exposure, unable to use a proven technology on almost 99% of their products.

  After extensive evaluation of the wholesomeness of irradiated food, a joint committee comprised of experts from the Food and Agriculture Organization, International Atomic Energy Agency and the World Health Organization sanctioned irradiation as a viable food process in 1981. Two of the report's conclusions were of major importance: 1) "Irradiation of any food commodity up to an overall average dose of 10 kGy presents no toxicological hazard, hence, toxicological testing of foods so treated is no longer required"; and 2) "Irradiation of food up to an overall average dose of 10 kGy introduces no special nutritional or microbiological problems."

  Contrary to this report, the U.S. Congress decided to include irradiation as a food additive in the Food Additives Amendment of the Federal Food, Drug and Cosmetic Act. As a result, each new food category or class proposed for irradiation requires the submission of a formal petition to the FDA, complete with suggested dosages, purpose of treatment, effect on nutritional value, safety data, and a review of all published literature. The petition process typically takes a minimum of two to three years, but often takes longer.

  Foods currently approved by the FDA for irradiation fall into just a handful of very specific categories, listed under 21 CFR section 179. These include fresh fruits and vegetables, enzymes, spices and dehydrated vegetable seasonings, fresh or frozen uncooked poultry, uncooked pork, and frozen, packaged meats for NASA space-flight programs. The FDA approved fresh and frozen red meat for irradiation in December 1997, and the USDA has announced plans to issue its final regulations by the end of 1999.

  While the list of foods approved for irradiation is still highly restricted, many food companies demand that component products - dry spices and dehydrated vegetable seasonings, as well as packaging - be irradiated as a preventive measure. For example, spice-containing salad dressings that will not be further processed often include irradiated spices to mitigate contamination concerns. And, with the demand for convenient condiments and fresher foods, more and more processors are using irradiated food packaging as an upstream preventive measure.

  The food processing industry increasingly employs the same clean-room technologies as the medical industry to ensure the highest levels of product safety and purity. This bodes well for irradiation. As product quality increases, dosage levels and irradiation costs decrease, making irradiation an even more viable solution for the control of pest infestation, reduction of foodborne pathogens and improvement of shelf life.

  Christine Bruhn, Ph.D., director of the Center for Consumer Research at the University of California, Davis, states: "Attitude studies have demonstrated that when given science-based information, from 60% to 90% of consumers prefer the advantages irradiation processing provides."

  Industry studies have found that 89% of shoppers are willing to pay a premium for irradiated pork to avoid trichinosis; 70% are willing to pay up to 5% more for irradiated hamburger meat; and 77% are willing to pay more for irradiated poultry.

  What's more, recent market tests have demonstrated that if informed and given a choice, consumers readily accept irradiated products. In California, consumers chose irradiated papayas over untreated ones 10 to one, purchasing 150 lbs. of the irradiated product in a single day. Likewise, in suburban Chicago, given a clearly marked choice, shoppers chose irradiated strawberries over non-irradiated ones nearly 30 to one. Some 2,000 flats of irradiated strawberries were sold in a single weekend.

  Perhaps one of the most positive changes affecting irradiation today is the mobilization of the food industry. More major players are joining forces to educate the public and to change government restrictions through a variety of methods. Their ultimate goal? To make irradiation just another powerful and accessible tool in the arsenal against microbial contamination. If the government lifted the severe restrictions on irradiation, the target food and applicability of the process would determine which process to employ, whether irradiation, canning, freezing or other means.

  The Food Irradiation Coalition, Washington, D.C., founded by the American Meat Institute and National Food Processing Association, is actively seeking to expand the availability and accessibility of irradiation for food processing. On August 23, 1999, in one of a continuing series of such moves, the coalition filed a petition asking the FDA to extend the use of food irradiation to RTE meat and poultry products and RTE fruit and vegetable products. More than two dozen leading food processor organizations, universities and irradiation companies co-sponsored the petition.

  Specific examples of foods covered by the petition include sprouts and seeds; juices; frozen fruits and vegetables; cut and packaged salads; refrigerated RTE meat and poultry products, and more.

  Traditionally, the technology and equipment focused primarily on medical-product applications. Accordingly, equipment was designed to deliver high dosages to low-density products. Food irradiation, however, requires the opposite - low dosages for high-density food items.

  New, food-specific irradiation services are fast becoming available. Enhanced conveyor capabilities reduce product handling and processing costs, while finely tuned systems deliver exceptionally low doses to high-density products. For example, SteriGenics, Fremont, CA, opened its Gilroy, CA food processing facility in August 1999. The facility's irradiation system features a customized material-handling system and a unique source-rack design allowing it to process a wide variety of food products at a range of doses.

  Others in the industry include MDS Nordion, Kanata, Ontario, with the industry's first irradiation system specifically targeted at meat processing; Food Technology Services, Mulberry, FL; and Steris Corporation, Mentor, OH. These companies are helping advance the state-of-the-art in irradiation food processing.

  One of the most promising developments on the horizon is the potential use of x-rays as an irradiation source. Like electron beams (e-beams), the energy source for x-rays is machine-generated rather than radioisotope-generated. Also, because x-rays are like gamma rays, they possess the superior penetration characteristics of gamma rays. Accordingly, x-ray processing is currently being considered for the purification and processing of a diverse array of products and foods.

  SteriGenics is currently expanding its capacity in the northeastern United States to include a Rhodotron®, a high-powered e-beam accelerator with x-ray capabilities. Scheduled to open in the second half of 2000, the facility will be the first to offer x-ray technology to the food industry. To make these services more cost effective and accessible to customers, Ion Beam Applications s.a., Louvain-la-Neuve, Belgium, is submitting a petition to the FDA to increase allowable x-ray voltage from 5 million electron volts (MeV) to 7.5 MeV.

  With dozens of countries relying on irradiation to protect their food supply, and more and more U.S. consumers and industry groups demanding access to the technology, there has never been a time when irradiation has held so much promise for so many people. Food processors, facing increased liability, though continuing to improve the quality of their manufacturing processes, recognize the added assurance irradiation offers, and are evaluating where, when and how they can incorporate this technology. Consumers, becoming more educated about irradiation's benefits, continue to demonstrate a willingness and desire to buy irradiated foods. Clearly, the time for irradiation is now.

  Thomas J. Mates, director of Western and Asian operations of SteriGenics' Advanced Applications Division, has over 25 years experience in the contract sterilization industry, including both gamma sterilization and ethylene oxide fumigation. He received his bachelor of science degree from Marquette University, and is an active member of the American Spice Trade Association (ASTA), the Refrigerated Foods Association and the Institute of Food Technologists. He also serves as chairman of ASTA's Food Ingredients Council.

The authors may be reached by calling SteriGenics at 800-777-9012.