Refrigeration & Equipment Engineering

Unit 8 - Irradiation

8.1.Introduction
Radiation processing of food involves exposure of food to short wave energy to achieve a specific purpose such as extension of shelf-life, insect disinfestations and elimination of food borne pathogens and parasites. In comparison with heat or chemical treatment, irradiation is considered a more effective and appropriate technology to destroy food borne pathogens. It offers a number of advantages to producers, processors, retailers and consumers.

Radiation processing of food has been thoroughly and extensively studied in order to ensure its toxicological, nutritional and microbiological safety. The data available from the world wide research including that from India over the last four decades was jointly reviewed by the experts of WHO, FAO and IAEA in a series of international meetings. In 1980, the joint FAO/IAEA/WHO Expert Committee on the wholesomeness of radiation processed food, convened in Geneva concluded that any food irradiated up to a maximum dose of 10kgy is safe for human consumption. Independent technical and scientific committees constituted by several countries including Canada, Denmark, France, India, Sweden, the UK, European Economic Community (EEC) and the US FDA have declared that radiation processed food is safe for human consumption.

Radiation processing of food involves the controlled application of energy from ionizing radiations such as gamma rays, electrons and X-rays for food preservation. Gamma rays and X-rays are short wavelength radiations of the electromagnetic spectrum which includes radio waves, microwaves, infrared, visible and ultra violet light. Gamma rays are emitted by radioisotopes such as Cobalt-60 and Caesium-137 while electrons and X-rays are generated by machines using electricity.