THE FOLKS AT Laurenzo`s Farmer`s Market in North Miami Beach made a bit of fruit history last month with a sale on Puerto Rican mangoes.
It was the first produce treated with gamma rays to be sold on the open market in the United States. Though other countries have been selling irradiated foods for years, Americans have been slow to adopt the technology, even though it was developed in this country.
That may be changing. The federal Food and Drug Administration (FDA) last year adopted rules that allow for irradiation of pork to control the parasite that causes trichinosis. And this spring, the FDA approved irradiation of fruits and vegetables to control insects and to slow growth and ripening.
It also approved using radiation to kill insects and microogranisms in herbs, spices, seeds, teas and vegetable seasonings. And pending are requests to make irradiation of seafood, poultry and a wide range of other foods accepted practice in this country.
The trend to more and more treatment of food with irradiation is opposed by groups who contend that not enough studies have been done to ensure that irradiated food is safe and nutritious.
Opponents also contend that the trend will lead to further dispersal of dangerous radioactive materials, which could result in nuclear accidents and hazardous pollution. They are backing federal legislation to reverse the FDA actions and to put a hold on the entire technology until its long-range consequences can be further studied.
But advocates of irradiation say that studies show the process is safe and that it replaces alternatives, such pesticides, that are known sources of toxicity in food and pollution in the environment.
Irradiation consists of exposing food to gamma rays, X-rays or some other form of ionizing energy, such as electron beams, to kill insects or microbes or to halt the ripening process in fruit. Exposing food to cobalt-60, a radioactive element that gives off gamma rays, is the most common procedure.
The gamma rays passing through the food break chemical bonds between atoms. This break-up of chemical bonds destroys the genetic material within microbes or insects, killing them or preventing normal reproduction. It also alters some molecules within the food itself.
The technique, which generates little heat, has long been used as a means of sterilizing instruments and supplies used in medical care. Advocates of irradiation predict that within five years the technology could become as common as canning or freezing to sterilize and preserve food.
It could reduce the need for preservatives known to have toxic effects, such as nitrites in bacon, and give some foods a shelf life of years, advocates say.
For David Liff, produce manager at Laurenzo`s in North Miami Beach, the debate over the benefits and risks of irradiation is a bit academic. His decision to market irradiated Puerto Rican mangoes drew some media attention to the market, but more important to Liff, it scored a hit with his customers. Though selling for $1.49 a pound, half a dollar more than Florida mangoes, the imported fruit sold briskly because of its superior appearance and flavor, Liff said.
”People who bought the fruit at first to try it came back again and again to buy more,” Liff said.
The irradiation didn`t seem to bother most people, he said, though a few said they were afraid of exposure to radiation from the fruit, a groundless fear, both advocates and opponents of food irradiation agree. Food that is irradiated is no more radioactive after leaving the energy field than is a person who undergoes a dental X-ray.
It is possible to make an object radioactive by bombarding it with ionizing energy, but the amount of energy required is much higher than anything used for sterilizing food or examining a patient, studies show.
”I wouldn`t order a product just because it was irradiated,” said Liff, ”but I would get irradiated produce again if that was the best way to get a quality product.”
In the case of the mangoes, irradiation was used instead of quarantining the fruit and treating it with pesticides or poison gases to prevent foreign insects from getting into the United States.
Research into food irradiation was initiated shortly after World War II by the U.S. Army, which wanted to feed its troops something more appetizing than traditional rations and was looking for new ways to preserve food. Research eventually brought forth the irradiation techniques used by the nation`s space agency to feed astronauts during missions in orbit or to the moon.
Irradiation of potatoes, to inhibit sprouting, and wheat and flour, to kill insects, has been approved in this country since the 1960s. But foreign countries have been much quicker to adopt the technology commercially. Nineteen nations have endorsed irradiation for a wide variety of foods.
After much testing, researchers in the U.S. government and the food industry repeatedly have concluded that the process is safe and effective.
The recent FDA actions represent an implementation of those findings. Also, a report issued in July by the Council for Agricultural Science and Technology (CAST), an amalgamation of several agricultural and academic societies, documents the safety and value of food irradiation.
Though there is no question of radiation exposure to humans who eat irradiated foods, critics raise several other questions about the safety of the process and warn that it must be stopped before the food industry invests huge sums and becomes committed to irradiation.
Groups such as the Health & Energy Institute, based in Washington, and the National Coalition to Stop Food Irradiation, based in San Francisco, contend that not enough is known about the effects of irradiation. It is premature to declare the process is safe, they say.
When food molecules are broken by radiation, byproducts called radiolytic products are formed, and these include such toxic substances as benzene and formaldehyde, the critics say. Some nutritional value of food is lost when it is irradiated. Critics say these facts alone are sufficient to warrant a moratorium on food irradiation until more is learned about long-range effects. Researchers at CAST and the FDA agree that some nutrients may be lost and that some radiolytes are formed, but they contend that toxins are also found in foods that are cooked and in foods that aren`t processed in any way.
Food nutrients also may be lost during storage, freezing or cooking, the researchers have found, and the loss of nutrients during irradiation isn`t deemed significant. In addition, research has uncovered several ways to minimize nutrient losses. Meat that is irradiated while frozen and then put in an oxygen-free container loses almost no vitamins, for example.
Advocates of irradiation say that it will actually make our food safer by retarding spoilage, destroying dangerous microbes and controlling insects–all without the use of food additives, pesticides or toxins now added to food for that purpose. It also will lower costs by making storage easier and reducing waste, they say.
Another criticism of food irradiation is that it will introduce large amounts of hazardous material such as cobalt-60 into communities all over America where food irradiation plants will be built.
While such substances are routinely used in nuclear medicine departments of hospitals nationwide, food processing requires quantities of dangerous materials far greater than anything required by medicine, posing problems of transportation, storage and disposal, critics say.
Mark Robinowitz of the Health & Energy Institute, a public interest group, argues that food irradiation plants already have been associated with spills of radioactive water into public sewers and with illegal disposal of such wastes into regular garbage cans, instead of being disposed of properly. Critics also charge that the FDA`s approval of food irradiation misleads the public. Those regulations require that irradiated foods carry a label saying that they have been treated with radiation as well as an international symbol–a plant sitting in a partially broken circle–that denotes such processing.
After two years, however, only the symbol will be required–on the theory that during that time people will become familiar with its meaning.
”The FDA action is a sham,” said Denis Mosgofian, director of the National Coalition to Stop Food Irradiation. ”It doesn`t cover foods that contain some irradiated ingredients. If you buy a pizza with spices that have been irradiated, the label won`t tell you. You won`t know how to avoid eating these foods.”
Also, Mosgofian said, it will take the industry a year or more to gear up for widespread irradiation of whole foods, so that by the time the practice becomes widespread, the two-year labeling requirement will have expired.
Such criticism, said Jim Green, an FDA spokesman, demonstrates a misunderstanding of the purpose of labeling.
”This isn`t some kind of warning label,” Green said. ”We require a warning on foods containing saccharin because studies have shown it is associated with cancer. We would have banned saccharin but Congress intervened, so we have a warning label.”
The FDA has found irradiation safe and effective as a food-processing technique. It is comparable to canning or freezing in the eyes of the agency. The purpose of the label, Green said, is simply to alert a consumer that a product that may look to be completely natural has been subject to food processing.
The mangoes sold in North Miami Beach were labeled as irradiated because they gave no outward appearance of having been processed, Green said. ”When someone buys a frozen pizza, he can see it`s been processed, so we don`t feel the need to put a label on the pizza to tell him that,” he said.
A broad proposal to allow sterilization of meats and vegetables with irradiation and to use it to extend the shelf life of seafood is pending before the FDA. It is also expected that the U.S. Department of Agriculture will file a petition soon to use irradiation to kill the salmonella bacteria in poultry.
George Giddings, director of food irradiation at Isomedix Inc., a firm with irradiation plants in several cities, including the Chicago suburbs of Morton Grove and Libertyville, said he expects the poultry proposal will receive the swiftest action from the FDA ”because there is a public health consideration associated with it.”
Giddings also said that he expects irradiation processing will take off soon as a result of past and predicted FDA actions approving its use. He sees a day when products such as meats will have an almost limitless shelf life, with no need of refrigeration. The containers will be vacuum packed and the food sterilized.
”The other day I opened a package of ham that was 14 years old and ate it on camera for benefit of a television crew,” he said. ”It was luscious.” As irradiation becomes more popular, more technological advances are likely. At present, use of electron beams plays a small role in the process because the beams don`t penetrate deeply into a food. In the future, Giddings said, this type of ionizing energy should become much more widely used in specialized applications. One might be preserving bacon without the use of additives known to have an association with cancer.
Unless critics are successful in getting legislation to stop it, irradiation technology seems destined to become a significant component of food processing, experts in the industry and government regulators agree.
