8-3

**Radiation Wiki** //<---Previous Assignment - Next Assignment--->media type="custom" key="6581827"//
 * __Time Length__ **
 * 1 Day
 * __Instructions__ **


 * 1) On your wiki, make a new page titled "8-3 Radiation Wiki"
 * 2) Read the information below and summarize it in 1 paragraph (5-10 sentences)
 * 3) **Do not copy and paste, unless you are quoting. I want your words, not someone else's.**
 * 4) Add a picture of radiation being used in the way you wrote about.

Food Irradiation: What Is It?
North Central Regional Extension Publication 437. Sponsored by the Extension Services of Iowa, Nebraska, South Dakota and Wisconsin in cooperation with ES-USDA. For copies of this publication, contact an Extension unit in one of the sponsoring states. Reprinted March 1993. Programs and activities of the Cooperative Extension Service are available to all without regard to race, color, sex, age, religion, national origin, or handicap. Radiation is broadly defined as energy moving through space in invisible waves. Radiant energy has differing wavelengths and degrees of power. Light, infrared heat, and microwaves are forms of radiant energy. So are the waves that bring radio and television broadcasts into our homes. Broiling and toasting use low-level radiant energy to cook food. The radiation of interest in food preservation is ionizing radiation, also known as irradia-tion. These shorter wavelengths are capable of damaging microorganisms such as those that contaminate food or cause food spoilage and deterioration. That capability, plus the fact that much of our food supply is lost due to spoilage and insects each year is why scientists have been experimenting with irradiation as a method of food preservation since 1950. They have found irradiation to be a controlled and very predictable process. As in the heat pasteurization of milk, the irradiation process greatly reduces but does not eliminate all bacteria. Irradiated poultry, for example, still requires refrigeration, but would be safe longer than untreated poultry. Strawberries that have been irradiated will last two to three weeks in the refrigerator compared to only a few days for untreated berries. Specially constructed containers or compartments are used to confine the beams so personnel won't be exposed. Radioisotopes are used in medical research and therapy in many hospitals and universities. They require careful handling, tracking, and disposal. Machines that produce high-energy beams offer greater flexibility. For example, they can be turned on and off unlike the constant emission of gamma rays from radioisotopes. Irradiation is known as a cold process. It does not significantly increase the temperature or change the physical or sensory characteristics of most foods. An irradiated apple, for example, will still be crisp and juicy. Fresh or frozen meat can be irradiated without cooking it. During irradiation, the energy waves affect unwanted organisms but are not retained in the food. Similarly, food cooked in a microwave oven, or teeth and bones that have been X-rayed do not retain those energy waves. Irradiation has been approved for many uses in about 36 countries, but only a few applications are presently used because of consumer concern and because the facilities are expensive to build. In the United States, the Food and Drug Administration (FDA) has approved irradiation for eliminating insects from wheat, potatoes, flour, spices, tea, fruits, and vegetables. Irradiation also can be used to control sprouting and ripening. Approval was given in 1985 to use irradiation on pork to control trichinosis. Using irradiation to control Salmonella and other harmful bacteria in chicken, turkey, and other fresh and frozen uncooked poultry was approved in May 1990.
 * Irradiation can be compared to pasteurization**
 * Two things are needed for the irradiation process**
 * 1) A source of radiant energy, and
 * 2) a way to confine that energy.For food irradiation, the sources are radioisotopes (radioactive materials) and machines that produce high-energy beams.
 * What happens when food is irradiated?**
 * What foods are irradiated?**

The term irradiation often evokes fears of nuclear radioactivity and cancer among consumers. The process seems frightening because it is powerful and invisible. Consequently, questions and concerns exist, particularly about the safety or wholesomeness of irradiated food. Here are some commonly asked questions. No, but the similarity between the two words is confusing. It is physically impossible for irradiated food to be radioactive just as your teeth are not radio-active after you have had a dental X-ray. Irradiation is radiant energy. It disappears when the energy source is removed. Over the past 30 years, researchers in several countries have evaluated irradiated foods for chemical products (radiolytic products) which may have formed. The toxicity of those products has been studied also. Because the irradiation process works with both large and small quantities, it has a wide range of potential uses. For example, a single serving of poultry can be irradiated for use on a space flight. Or, a large quantity of potatoes can be treated to reduce sprouting during warehouse storage. However, irradiation cannot be used with all foods. It causes undesirable flavor changes in dairy products, for example, and it causes tissue softening in some fruits, such as peaches and nectarines. Irradiation is most useful in four areas. Irradiation can be used to destroy or inactivate organisms that cause spoilage and decomposition, thereby extending the shelf life of foods. It is an energy-efficient food preservation method that has several advantages over traditional canning. The resulting products are closer to the fresh state in texture, flavor, and color. Using irradiation to preserve foods requires no additional liquid, nor does it cause the loss of natural juices. Both large and small containers can be used and food can be irradiated after being packaged or frozen. Foods that are sterilized by irradiation can be stored for years without refrigeration just like canned (heat sterilized) foods. With irradiation it will be possible to develop new shelf-stable products. Sterilized food is useful in hospitals for patients with severely impaired immune systems, such as some patients with cancer or AIDS. These foods can be used by the military and for space flights. In this role, irradiation offers an alternative to chemicals for use with potatoes, tropical and citrus fruits, grains, spices, and seasonings. However, since no residue is left in the food, irradiation does not protect against reinfestation like insect sprays and fumigants do. Irradiation can be used to effectively eliminate those pathogens that cause foodborne illness, such as Salmonella. All methods used to process and preserve foods have benefits and limitations. Some possible applications for irradiation with certain foods are shown in Table 1. Opponents of irradiation worry that these radiolytic products are hazardous. Biochemical and biomedical tests have not been able to identify any health prob-lems or ill effects associated with tested radiolytic compounds. The Food and Drug Administration (FDA) regulates all aspects of irradiation: what products it can be used on, what dose can be used, and how those products are labeled. The U.S. Department of Agriculture (USDA) is responsible for the inspection and monitoring of irradiated meat and poultry products and for the enforcement of FDA regulations concerning those products. Since 1986, all irradiated products must carry the international symbol called a radura, which resembles a stylized flower.
 * ~ Table 1. Potential food irradiation uses ||
 * ~ Type of food ||~ Effect of Irradiation ||
 * Meat, poultry || Destroys pathogenic fish organisms, such as Salmonella, Campylobacter and Trichinae ||
 * Perishable foods || Delays spoilage; retards mold growth; reduces number of microorganisms ||
 * Grain, fruit || Controls insect vegetables, infestation dehydrated fruit, spices and seasonings ||
 * Onions, carrots, potatoes, garlic, ginger || Inhibits sprouting ||
 * Bananas, mangos,papayas, guavas, other non-citrus fruits || Delays ripening avocados, natural juices. ||
 * Grain, fruit || Reduces rehydration time ||
 * What concerns are raised by opponents of food irradiation?**
 * Are irradiated foods radioactive?**
 * Are toxic radiation products produced?**
 * What are some potential applications for food irradiation?**
 * Preservation**
 * Sterilization**
 * Control sprouting, ripening, and insect damage**
 * Control foodborne illness**
 * How is food irradiation regulated?**