It is not new; interest was shown in Germany in 1896 (Stewart, 2004(a)) and it began in the early 1920s, while in the 1950/60s the US Army Natick Soldier Center (NATICK) experimented with both low dose and high dose irradiation for military rations.In the UK, at the same time, the Low Temperature Research Station programme concentrated on low dose pasteurisation (Hannan, R S 1955).
In all but very dry matter, such as bone or shell, small amounts of substances are formed, some of which are highly active but transient free radicals, others of which are useful as markers which can be used to determine whether or not the food has been irradiated.
It is the action of the transient free radicals, which accounts for much of the effects (killing pathogenic bacteria, extending shelf-life, etc) of irradiating food.
Irradiation is extensively used in the medical field for sterilising instruments, dressings, etc.
Food irradiation is the process of exposing food to a carefully controlled amount of energy in the form of high-speed particles or electromagnetic radiation.
Food irradiation is slowly gaining consumer acceptance in the US and several other countries but it is slow to gain support within many parts of Europe, including the UK, where the Food Standards Agency (FSA) recommends no extension of application.
Many consumers are initially hostile to irradiation but when the process is explained to them they become generally more in favour.
Thus, parasites such as tapeworms and disease-causing microorganisms such as species (both of which will occasionally be found in raw food) can be controlled or destroyed by irradiation.
In much the same way, ionising radiation can slow down cell-based processes such as early ripening in fruit, which would lead to premature decay.
However, this initial positive list has only one food category – dried aromatic herbs, spices and vegetable seasonings.
Some countries, such as Belgium, France, The Netherlands and the UK allow other foods to be irradiated, whereas other countries, such as Denmark, Germany and Luxembourg remain opposed.