Irradiation can improve the quality, variety, and safety of foods. Although other processing plant measures can reduce bacteria levels in raw foods, irradiation is more effective because it can eliminate pathogens such as E. coli 0157:H7, especially important for consumers who prefer their meat medium or rare. Unlike cooking, which also can eliminate pathogens, irradiation does not change the fresh character of foods. In fact, it extends the freshness of foods, delays the ripening of fruit, and prevents the sprouting of vegetables.
Food irradiation is the process of exposing food products to ionizing radiation for a specified length of time. The amount of exposure is controlled to produce various preservation effects, such as retarding spoilage or killing any harmful bacteria. It serves as a complement to good manufacturing practices such as quality control, and is part of an overall food safety protection system. Just as potentially harmful bacteria in milk are killed through pasteurization using heat, irradiation kills most harmful bacteria in other foods. In fact, food irradiation is often called “cold pasteurization” because it destroys bacteria without the use of heat.
Food irradiation has been studied for more than 40 years and has not been found to cause harm to human health. People requiring the safest food, such as hospital patients receiving bone marrow transplants, are given irradiated foods. American astronauts on space missions have eaten irradiated foods since 1972. Irradiated wheat flour, potatoes, and spices have been available for more than 18 years.
Food irradiation is the most extensively studied food processing technology available. The first patents for food irradiation were granted in the United States and the United Kingdom in 1905. Since then, the U.S. government and other governments worldwide have reviewed hundreds of studies on the effects of food irradiation.
In the United States, the FDA has approved food irradiation to extend shelf-life and to kill microbial pathogens. Food irradiation has been approved for fruits, vegetables, grains, spices, poultry, beef, pork, and lamb. In fact, the U.S. has one of the most regulated policies on food irradiation processes in the world. In addition to receiving FDA approval, the safety of food irradiation and its use for a wide range of food products has been accepted by the World Health Organization, the American Medical Disease Control and Prevention, The American Association’s Council on Scientific Affairs, the Centers for Disease Control and Prevention, The American Dietetic Association, the Food and Agriculture Organization of the United Nations and the International Atomic Energy Agency. Worldwide, food irradiation has been approved by about 40 countries.
Irradiated wheat flour, potatoes, and spices have been available for more than 18 years. More recently, irradiated produce and poultry have been sold in some American supermarkets. Following the FDA approval of food irradiation for beef, pork, and lamb in December 1997, meat processing guidelines were developed by the USDA. Currently, consumers can buy irradiated foods locally in many areas of the U.S. Available irradiated products include chicken, fruits, spices, and ground beef. In Europe, over 40 types of irradiated foods are being purchased by consumers.
Food moves through a radiant energy field, but never touches the energy source. The amount of energy and type of radiation used to irradiate foods is enough to kill foodborne bacteria but does not make the food itself radioactive. In fact, electron sources and x-rays do not even use a radioactive isotype. Think of the irradiation process as the way a luggage scanner works when you go through a security checkpoint at the airport.
Although irradiation at the doses approved by the FDA does not sterilize food, it protects from spoilage or potentially harmful bacteria in the same way milk is protected through pasteurization. As with any food product, foodservice workers and consumers must follow safe handling and preparation guidelines to ensure food safety. These safe food handling measures include washing hands and cleaning preparation surfaces often, separating foods to avoid cross contamination, cooking foods thoroughly, and refrigerating and storing foods properly.
Since food irradiation was approved in the United States in the early 1960’s, there have been numerous studies on consumer understanding and acceptance of food irradiation. An early 1990’s study at Purdue University demonstrated that once consumers understand the food irradiation process (in this study, by watching an educational videotape at the supermarket) over 90 percent are willing to purchase foods processed with irradiation. A 1998 nationwide survey found that 80 percent of consumers would purchase food labeled “irradiated to destroy harmful bacteria.” One-third to one-half of consumers have some degree of awareness of the process of food irradiation. Of those who have a higher level of awareness of the process, about two-thirds indicate they would be willing to purchase food treated with irradiation for its safety benefits.
Irradiation produces virtually no heat within foods and does not “cook” foods. Foods processed with irradiation are just as nutritious and flavorful as other foods in the marketplace. In fact, processing by irradiation produces changes in nutrient content and flavor that are the same or lower than those produced by cooking, canning, or freezing.
Irradiated food is extremely cost effective. The United States Department of Agriculture estimates that American consumers will receive approximately $2 in benefits such as reduced spoilage and less illness for each $1 spent on food irradiation.