For radiation foods processing various radioisotopes are used in food radiation high energy electromagnetic radiation such as X-rays and r- rays of accelerated electron beams having energy upto 10 million electron volts. By penetration in the cells of micro-organisms. The radiations cause structural and functional changes in bimolecular leading to cell death Radio-active nucleosides, cobalt-60 and caesium-137 have been selected internationally as gamma rays sources, taking into their economic, availability and safety.

The irradiation of food provides protection against food borne illness. It is the only technique which can kill bacteria residing within a food item without damaging the product. Irradiation helps to preserve food, control sprouting of items such as potato, onion and control food borne disease. It also inactivates organisms that cause spoilage and extends life of foods. Also food irradiation is essentially a cold process and nutrient losses are significantly less than those associated with canning, drying and heat pasteurization. Some patients with poor immunity and astronauts eat only irradiated foods.