The most promising food safety technology since pasteurization is food irradiation. The concept is simple: food of many varieties is processed with ionizing radiation, which kills bacteria and parasites that could otherwise make humans sick or cause the food to rot more quickly. Irradiated meat stays pink longer, and contains no bacteria that could cause food poisoning. Irradiated fruits can stay fresh for up to three weeks; imagine strawberries that stay fresh and free of mold for that long!
Food irradiation was first studied as an application to keep astronauts from getting sick, and all space-bound food is irradiated first. Scientists have found that irradiation greatly reduces or entirely eliminates causes of disease on food without changing the nutritional value of the food. Though the food is slightly changed during the irradiation treatment, it does not become radioactive and no dangerous substances are produced in it.
If all raw meat was treated with irradiation at the slaughterhouse, most bacteria that causes food poisoning (resulting in thousands of hospitalizations and hundreds of deaths each year) could be eliminated; this includes E. coli, salmonella, and campylobacter, the three most dangerous food toxins. Listeria could be eliminated from hot dogs and deli meat. Cyclospora, shigella, and salmonella could be eliminated from fresh produce without harming the produce in any way. Dry foods like grains could be protected from micro-organisms and the eggs and larva of many bugs, as well as preventing the initial contamination of livestock with salmonella and other bacteria.
There are three techniques used today for food irradiation. Gamma rays, using radioactive cobalt or cesium, are targeted at foods and penetrate up to several feet, in the same process that has been used for decades in medical and dental sterilization. Because these radioactive materials give off photons but not neutrons or other particles, there is no danger of making irradiated substances radioactive, just as sunlight cannot make most substances glow in the dark.
Electron beams use a stream of high-energy electrons to shoot the food, but cannot penetrate deeply into food, making this process better for surface irradiation. X-ray irradiation, the third method, starts with an electron beam, but aims them at a thin plate of metal to produce X-rays from the other side of the plate; this process can also penetrate food deeply, and unlike gamma irradiation, the source of the radiation can simply be shut off.
Once treated, all living cells in the food should be dead. This means that dangerous bacteria are killed, but it also means that potatoes and other root vegetables will no longer sprout, extending their shelf lives. Thiamin in foods may be reduced, but not in enough amounts to result in a vitamin deficiency; other vitamins, such as vitamin A, may actually be increased. There are no other significant changes in the food, and in fact it can be difficult to tell irradiated food from food that has not been irradiated. Irradiated foods can pick up germs in handling, but as packaged they should be completely safe.
Irradiation has been endorsed by the World Health Organization, Centers for Disease Control and Prevention, the U.S. Assistant Secretary of Health, the U.S. Department of Agriculture, the Food and Drug Administration, and the American Physicians Association.
And yet – despite years of study, sweeping approvals and endorsements, and extensive use for limited projects, irradiated food is not commonly sold. Instead, hundreds of people in the United States alone die each year from food poisoning, and tons of food is wasted due to spoilage.
In Florida, one facility has been irradiating strawberries and fruits. A Hawaiian plant irradiates fresh tropical fruits instead of fumigating them to prevent fruit flies from traveling to the mainland with them. Commercial spices are also often irradiated.
For foods that aren’t irradiated, toxic substances, such as fungicides and insecticides, are commonly applied to kill off unwanted substances. And foods that are irradiated are clearly market as irradiated foods.
The problem is, when people hear the word “radiation” and “irradiated,” they instantly get an image in their heads of glowing babies. Well-meaning but ill-informed consumer groups have played on this image, and since they are usually the ones sending press release to your local news station (not the CDC), most stores are frightened away from using irradiated food before the public has a chance to decide.
But in test marketing, about eighty percent of consumers will buy irradiated products. Even half of consumers who are not well educated about how irradiation works and what it does to food will still purchase it if given a choice between irradiated and nonirradiated foods. In fact, other countries are already irradiating food, including France, the Netherlands, Portugal, Israel, Thailand, Russia, China, and South Africa.
The other problem with irradiation is that the facilities to irradiate food can be fairly expensive to build, though their operation is not too bad. Once consumers start to show an interest in irradiated foods, it is likely that irradiated food will become common, just as pasteurized milk is today.