Principle of food irradiation process

Generally, irradiation is the practice of exposing food a controlled amount of radiant energy to increase the safety of the food and to extend shelf life of the food. Treating food with ionizing radiation can kill bacteria and parasites that would otherwise cause foodborne disease.

It was first suggested in 1897, 1-year after Roe¨tgens discovered X-rays and it was patented in England in1905. From 1940 to 1960, research was conducted at the quartermaster laboratory of the US Army to provide sterilized cans to the US army.

In 1962, the first food irradiation facility was built for the army and the USDA issued the first food irradiation rules in 1963 to decontaminate wheat and wheat powder.

Sources of Ionizing irradiation are: Gamma rays, X-rays, Electrons (Radura). When radiation strikes other material, it transfers energy, it knocks electrons out of the material bombarded, breaking the molecular structure-thus leaving ions (free radicals) hence the name ionizing radiation. It kills microorganism by destruction of DNA and by creating toxic reactive compounds in a medium and in microbial cells. Irradiation kills bacteria, spores and insects as well as inactivates enzymes.

Advantages of irradiation:
*Less nutritional losses
*The chemical reactions associated with food irradiation do, in fact, produce very small amounts of new compounds called radiolysis products.
Principle of food irradiation process