What is Food Irradiation?Food irradiation is a promising new food safetytechnology that can eliminate disease-causingmicroorganisms such as E. coli O157:H7,Campylobacter, and Salmonella from foods.

The Food and Drug Administration has approvedirradiation of meat and poultry and allows its use for avariety of other foods, including fresh fruits andvegetables, and spices. The agency determined thatthe process is safe and effective in decreasing oreliminating harmful bacteria. Irradiation also reducesspoilage bacteria, insects and parasites, and in certainfruits and vegetables it inhibits sprouting and delaysripening.

The effects of irradiation on the food and on animalsand people eating irradiated food have been studiedextensively for more than 40 years. These studies showclearly that when irradiation is used as approved onfoods:

Disease-causing microorganisms are reduced oreliminated

The nutritional value is essentially unchanged

The food does not become radioactive

Irradiation is a safe and effective technology that canprevent many foodborne diseases.

UW Food Irradiation Education Group

The FactsAboutFoodIrradiation

Why are we interested in food irradiation?

Presently over 40 countries have approved applicationsto irradiate approximately 40 different foods. Theseinclude such items as fruits, vegetables, spices, grains,seafood, meat and poultry. More than half a milliontonnes of food is now irradiated throughout the worldon a yearly basis. Although this amount represents onlya fraction of the food consumed annually, it is constantlygrowing. This trend is due to three main factors:

1. Increasing concerns over foodborne diseases

Foodborne diseases pose a widespread threat tohuman health and they are an important cause ofreduced economic productivity. Studies by the US Centerfor Disease Control in 1999 estimated that foodbornediseases cause approximately 76 million illnesses,325,000 hospitalizations, and 5,000 deaths in theUnited States each year. Economic losses associatedwith such foodborne diseases are high-estimatedbetween US $6.5 billion and $33 billion.

2. High food losses from infestation, contaminationand spoilage.

The FAO has estimated that about 25% of all worldwidefood production is lost after harvesting to insects,bacteria and spoilage. Economic losses due to insectsand microbes have been estimated to fall between $5and $17 billion yearly in the US alone. Food irradiationcan help reduce these losses and can also reduce ourdependence on chemical pesticides, some of whichare extremely harmful to the environment (e.g. methylbromide).

3. Growing international trade in food products.

As our economies become more global, food productsmust meet high standards of quality and quarantine inorder to move across borders. Irradiation is an importanttool in the fight to prevent the spread of deleteriousinsects and microorganisms.

This brochure has been prepared by the UW FoodIrradiation Education Group, based on the informationprovided by:

http://www.iaea.org/worldatom/inforesource/other/food/http://www.cdc.gov/ncidod/dbmd/diseaseinfo/foodirradiation.htmhttp://www.food-irradiation.com/http://www.fda.gov/

For more information:

Email: uw-food-irradiation@engr.wisc.eduURL: uw-food-irradiation.engr.wisc.edu

Does the irradiation process make foodradioactive?

No. Irradiation by gamma rays, X-rays and acceleratedelectrons under controlled conditions does not makefood radioactive. Just as the airport luggage scannerdoesnt make your suitcase radioactive, this process isnot capable of inducing radioactivity in any material,including food.

How do I know if food has been treated withirradiation?

Special labels are required on irradiated foods, includingthe international symbol of irradiation, known as aradura, and a statement indicating that the food wastreated with irradiation.

Can irradiation be used to make spoiledfood good?

No. Neither irradiation nor any other food treatment canreverse the spoilage process and make bad food good.If food already looks, tastes or smells bad - signs ofspoilage - before irradiation, it cannot be saved by anytreatment including irradiation.

How does irradiation affect food?

The process involves exposing the food, eitherpackaged or in bulk, to carefully controlled amounts ofionizing radiation for a specific time to achieve certaindesirable objectives.

When microbes present in the food are irradiated, theenergy from the radiation breaks the bonds in the DNAmolecules, causing defects in the genetic instructions.Unless this damage can be repaired, the organism willdie or will be unable to reproduce. It matters if the foodis frozen or fresh, because it takes larger radiation doseto kill microbes in frozen foods. The effectiveness of theprocess depends also on the organisms sensitivity toirradiation, on the rate at which it can repair damagedDNA, and especially on the amount of DNA in the targetorganism:

Parasites and insect pests, which have largeamounts of DNA, are rapidly killed by an extremelylow dose of irradiation.

It takes more irradiation to kill bacteria, becausethey have less DNA.

Viruses are the smallest pathogens that have nucleicacid, and they are, in general, resistant to irradiationat doses approved for foods.

If the food still has living cells, they will be damaged orkilled just as microbes are. This is a useful effect: it canbe used to prolong the shelf life of fruits and vegetablesbecause it inhibits sprouting and delays ripening.

Are irradiated foods still nutritious?

Yes, the foods are not changed in nutritional value andthey dont become dangerous as a result of irradiation.At irradiation levels approved for use on foods, levels ofthe vitamin thiamine are slightly reduced, but not enoughto result in vitamin deficiency. There are no othersignificant changes in the amino acid, fatty acid, orvitamin content of food. In fact, the changes induced byirradiation are so minimal that it is not easy to determinewhether or not a food has been irradiated.

A big advantage of irradiated food, is that it is a coldprocess: the food is still essentially raw, because ithasnt undergone any thermal process.

Are irradiated foods available now?

A variety of foods have been approved for irradiation inthe United States, for several different purposes. Formeats, separate approval is required both from the FDAand the USDA.

However, irradiated foods are not widely available yet.Some stores have sold irradiated fruits and vegetablessince the early 1990s. Irradiated poultry is available insome grocery storesmostly small, independentmarkets and on menus of a few restaurants. On theother hand, most spices sold wholesale in this countryare irradiated, which eliminates the need for chemicalfumigation to control pests. American astronauts haveeaten irradiated foods in space since the early 1970s.Patients with weakened immune systems aresometimes fed irradiated foods to reduce the chance ofa life-threatening infection.

In addition, irradiation is widely used to sterilize a varietyof medical and household products, such as jointimplants, band-aids, baby pacifiers, cosmeticingredients, wine and bottle corks, and food packagingmaterials.

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Does irradiation destroy all bacteria?

No. Irradiation is equivalent to pasteurization for solidfoods, but it is not the same as sterilization. Foodirradiation can be an important tool in the war againstillness and death from foodborne diseases. But it isnot a substitute for comprehensive food safetyprograms throughout the food distribution system. Inaddition, food irradiation is not a substitute for goodfood-handling practices in the home: irradiated foodsneed to be stored, handled and cooked in the sameway as unirradiated foods.

Will irradiation increase the cost of food?

Yes, any food processing method will add cost. Canning,freezing, pasteurization, refrigeration, fumigation, andirradiation will add cost to the food. These treatmentswill also bring benefits to consumers in terms ofavailability and quantity, storage life, convenience, andimproved hygiene of the food.

The increase in price for irradiated fruits and vegetablesis estimated at 2 to 3 cents per pound. Irradiated poultryand meat products are expected to cost 3 to 5 cents apound more than non-irradiated meat. The price is likelyto decline as irradiated foods become more widelyavailable.