Food Irradiation - Processing of Food By Ionizing Radiation

Processing of Food By Ionizing Radiation

By irradiating food, depending on the dose, some or all of the microorganisms, bacteria, viruses, or insects present are killed. This prolongs the shelf-life of the food in cases where pathogenic spoilage is the limiting factor. Some foods, e.g., herbs and spices, are irradiated at sufficient doses (five kilograys or more) to reduce the microbial counts by several orders of magnitude; such ingredients do not carry over spoilage or pathogen microorganisms into the final product. It has also been shown that irradiation can delay the ripening of fruits or the sprouting of vegetables.

Insect pests can be sterilized (be made incapable of proliferation) using irradiation at relatively low doses.

Some foods, particularly fruits and vegetables, are not available for sale on the global market unless treated to prolong shelf life for transportation. This may include radiation processing. This application has not yet been exploited. In contrast, irradiation to eliminate insect pests to fulfill quarantine requirements is gaining commercial significance.

Food irradiation is sometimes referred to as "cold pasteurization" or "electronic pasteurization" because ionizing the food does not heat the food to high temperatures during the process, as in heat-pasteurization (at a typical dose of 10 kGy, food that is physically equivalent to water would warm by about 2.5 °C). The treatment of solid food by ionizing radiation can provide an effect similar to heat pasteurization of liquids, such as milk. The use of the term "cold pasteurization" to describe irradiated foods is controversial, because pasteurization and irradiation are fundamentally different processes, although the intended end results can in some cases be similar.