From controlling pests in shipments of grains to increasing the shelf life of packaged foods to adding more choices to the dinner trays of hospital patients, food irradiation contributes to improving both food safety and food quality. The irradiation process itself consists of shining beams of electrons, X-rays or gamma rays on food in order to destroy micro-organisms and control spoilage. In doing so, irradiation actually provides the same benefits as heat, refrigeration or chemical treatment with the added advantages that:
- it does not raise temperatures significantly, so food does not “cook”, it does not affect taste, smell or texture of the food,
- it does not leave potentially harmful residues, unlike chemical treatments,
- it can be used to treat packaged foods, protecting them from subsequent microbial contamination or pest reinfestation.
In addition, irradiation can cut post-harvest food losses caused by insects, bacteria or mould, or by sprouting or over-ripening produce. These losses are estimated at between 25 and 40 percent of the harvest in many developing countries.
Food irradiation exposes food commodities to ionizing radiation under controlled conditions. Three major types of ionizing radiation are internationally recognized for the treatment of foods:
- gamma rays from the radionuclides cobalt-60 or caesium-137, and
- X-rays and electron beams generated from machine sources.
Irradiation does not completely sterilize food, but the many-fold reduction in micro-organisms helps prevent food poisoning while its ability to prevent sprouting and bacterial growth and to slow ripening reduces the waste that comes with spoilage. Also used as a quarantine treatment for insect pests, irradiation facilitates international trade of various fruits and vegetables by helping prevent the spread of insect pests of economic and environmental importance.
