Food Protection Connection: New: Irradiated Greens
Each Food Protection Connection article is approved for 1 hr CE (sanitation) for CDM, CFPPs and 1 CPE hour (level 1) for RDs and DTRs.
Earn CE for this by purchasing a CE form in the Marketplace
What is Irradiation?
FOOD IRRADIATION is an end-stage processing technique
used before food reaches a distribution point in the
farm-to-fork cycle of food management.
It involves exposing food to radiant energy, such as gamma rays, for a short time. This happens in an enclosed irradiation chamber. The energy from irradiation moves through the food, much as microwaves travel through food in a microwave oven.
As an example, it takes only a very small dose of radiation to destroy the trichinella parasite in pork. Doses are measured in kGy, or kiloGrays. A gray is a unit of measure used by physicists to describe how much ionizing radiation is absorbed by a substance. Effective doses depend on the food itself and the intended purpose, but all these uses are regulated. US standards for acceptable doses are among the lowest (or most stringent) in the world.
Source: DMA Food Protection Connection, Nov./Dec. 2001
International Food Information Council (IFIC). Food Irradiation: A Global
Food Safety Tool:
(reprinted from Dietary Manager, October 2008)
Effective August 22, 2008, the FDA has ruled that produce processors may treat spinach and iceberg lettuce with irradiation to enhance food safety. At the dosage being targeted, irradiation destroys E. coli, a major source of contamination and foodborne illness in salad greens over recent years. This is in response to a petition from the Grocery Manufacturers Association, and is a response to a petition affecting a number of food categories, originally submitted to the FDA in 2000.
Still under review by the FDA are other segments of the petition, including requests to allow irradiation for additional produce. Approval for Romaine lettuce, for example, would open up opportunities to treat salad mixes, according to industry analysts.
Food scientists have nicknamed food irradiation "cold pasteurization." Both food irradiation and traditional heatbased pasteurization (e.g., for milk and juices) use energy to destroy pathogens—without "cooking" the food. Pasteurization uses heat energy, while radiation uses radiant energy—high-energy beams of invisible waves. Neither leaves a residue. Both can improve food safety by destroying pathogens.
Any food processing technique comes under review for these key questions, and food irradiation has been a subject of research for decades now. Based on research and reviews, the FDA concludes that irradiated food retains its nutrient value and is safe to eat. Studies on nutrients show small losses, but these are less than losses from canning or pasteurization with heat, and can be partially controlled through technique, according to the International Food Information Council (IFIC).
Irradiation also creates chemical changes in food, forming unique compounds. According to the IFIC, "Based on hundreds of scientific tests, there is broad agreement among scientists and health agencies that these compounds are not a human health issue. In fact, more chemical changes occur when toasting bread or barbecuing steak than when irradiating food." (for reference, see "More Info" below)
At this time, food irradiation is a widespread practice around the world; 50 countries have adopted it. The World Health Organization states, "Food irradiation is a thoroughly tested process and when established guidelines and procedures are followed, it can help ensure a safer and more plentiful food supply." Another organization that has endorsed food irradiation is the American Dietetic Association.
Consumers are unsure, according to some industry research. Fears about irradiation may stem from a lack of understanding of the science behind the process. However, industry research suggests that with education, consumers embrace the added food safety protection.
Critics, such as Food & Water Watch and the Center for Science in the Public Interest, have raised concerns. A chief criticism is that we may rely on irradiation to cover up an array of food safety flaws. Proponents of the process, including the FDA, emphasize that irradiation is a complement to our array of food protection tools—not a substitute for sound procedures and HACCP systems.
The bottom line for dietary managers is that new options for controlling the E. coli hazard in spinach and iceberg lettuce are here, or coming soon. These products have the potential to strengthen a multi-pronged approach to protecting the health of your clients.
- Irradiation of spinach and iceberg lettuce is now allowed, but is NOT required.
- Use of irradiation for food is classified as a "food additive" for regulatory purposes, however, it is not a chemical ingredient added to food.
- Irradiated food is not radioactive.
- Radiation can also kill other bacteria, including Salmonella and Listeria. However, E. coli are most sensitive to its effects.
- Irradiation can extend shelf life of leafy greens by destroying some spoilage microorganisms.
- The Grocery Manufacturers Association suggests initial applications of this new rule may target high-risk populations.
- The FDA has already approved irradiation for red meats and other foods.
- Irradiation has been used to treat dried spices for decades.
- US food treated with irradiation must be labeled accordingly, with a logo called a radura, statement such as "Treated with irradiation or "Treated by irradiation."
Sue Grossbauer, RD, author of several books, and a regular contributor to DIETARY MANAGER magazine.