To zap or not to zap: The debate over food irradiation heats up
IMAGINE strawberries that stay fresh for 2 or 3 weeks, pork that doesn't need extra long cooking, chicken, shrimp, and vacuum-packed meat that can be kept outside the refrigerator for six to eight years. These are some of the promises of food zapped with radiation to preserve freshness, to kill insects and bacteria, a process that could become as common as canning, freezing, or microwaving by the year 2000, according to Prof. Richard Matthews of the University of Florida's Institute of Food and Agricultural Sciences.Skip to next paragraph
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But this rosy view is not unanimous.
Last month when a supermarket in North Miami, Fla., offered Puerto Rican mangoes that had been treated with gamma rays, it set off questions and controversy.
Although exposing some fruits and vegetables to low doses of radiation was approved by the United States Food and Drug Administration (FDA) in April, the process has been used mainly for spices and seasonings, until the recent sale of the irradiated mangoes.
``The food treatment process is simple,'' explains Dr. Matthews. ``Foods are put on a conveyor that exposes them to radiation inside a shielded chamber. Gamma rays from cobalt 60 or cesium 137 can be used, or foods can be exposed to X-rays or high-velocity electrons.''
Matthews cautioned that once exposed to these low doses of radiation, foods must still be refrigerated or handled like regular foods not treated with radiation.
It was more than 20 years ago that the FDA approved the radiation treatment of wheat, wheat flour, and potatoes. Dried spices and pork were given the OK in the 1980s. Other countries around the world have been selling some irradiated foods for years, but so far there has not been much available in the United States.
The major consumers of irradiated foods have been servicemen and astronauts on NASA's space shuttle, which has no refrigeration or cooking facilities.
Vacuum-sealed, irradiated steak, which could last two to three years, as well as irradiated rye bread, rolls, and other foods have been served aloft. Other consumers include hospital patients diagnosed as having low resistance to infection.
Overall, the commercial development of the food-irradiation process has been slow. But this is nothing new. American consumers have frequently been hesitant about accepting new food techniques.
It took more than 50 years for the canning process to become fully accepted and years for people to become accustomed to frozen foods.
``Irradiated foods are probably not going to make a big hit with most people right away,'' says Dr. Matthews.
``At best, consumer acceptance will be slow. And I believe the food industry itself will be conservative about adopting this new technology.''
Radiation is a scary word. The public winces at the thought of eating anything treated with radiation, even though scientists say there's no radioactivity created in food from the process.
Because it will extend the shelf life of certain foods, the new ruling is seen by some as a great service to consumers. Others, however, consider the practice of irradiating foods to be expensive, unsafe, and unneeded.
In spite of the FDA's approval, the process until now has been used mostly to preserve herbs and spices. But recently.
When irradiated mangoes appeared in Laurenzo's Farmer's Market in Miami Beach, owner David Laurenzo explained that fruits such as mangoes and papayas have been difficult to find in the US.
``We wouldn't be able to import Puerto Rican mangoes if they weren't treated,'' Mr. Laurenzo says. ``I believe it's a safe, good way to preserve the fruit a few days more.''
``Treated food can be eaten immediately,'' says George Giddings, director of food irradiation at Isomedix Inc., a company with plants in several cities and in Puerto Rico. ``It is absolutely impossible for any radiation to be still in the food -- the same as a radiation treatments to the human body. After it's over, it's over.''
``The radiation penetrates through the food and its packaging so that all portions are treated. No residues remain,'' Mr. Giddings says. ``There is essentially no temperature rise in the food. Frozen frogs legs and shrimp will not thaw while being decontaminated.
``The molecular changes that occur in foods at the FDA-approved one-kiloGray level are minimal: less than those that occur when foods are cooked or canned. The change of color and flavor of various spices are less than from fumigation, '' he says.