The process exposes foods to ionizing radiation that kills insects, moulds and bacterium. The technology, which can kill up to 99 per cent of pathogens, is seen by the industry as a means of ensuring food safety.
However public concerns over the health effects of the technology has meant global food companies have had to deal with a confusing thicket of legislation and restrictions when making and marketing their products.
While food irradiation is slowly gaining consumer acceptance in the US and several other countries, the technology has been slow to get support within many parts of Europe, including the UK, where the Food Standards Agency (FSA) recommends no extension of its application from current permitted uses.
The UK's Institute of Food Science and Technology (IFST), which published the legislative report, supports the use of irradiation. The method has been been endorsed as safe for foods and health by the World Health Organisation, the Food and Agricultural Organisation and the Codex Alimentarius, an international standards-setting body.
"Irradiation, carried out under conditions of good manufacturing practice, is commended as an effective, widely applicable food processing method judged to be safe on extensive available evidence, that can reduce the risk of food poisoning, control food spoilage and extend the shelf-life of foods without detriment to health and with minimal effect on nutritional or sensory quality," the IFST stated in the report.
Despite the evidence, regulators both within and without the EU have taken different approaches to allowing processors to use the technology.
To date, about 50 countries have approved about 60 products to be irradiated. The US, South Africa, the Netherlands, Thailand and France are among the leaders in adopting the technology.
Currently regulations on food irradiation in the European Union are not fully harmonised. Directive 1999/2/EC establishes a framework for controlling irradiated foods, their labelling and importation, while Directive 1999/3 establishes an initial positive list of foods which may be irradiated and traded freely between member states.
So far the 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, the IFST reported. Within the UK seven categories of foods can be irradiated to specified doses.
Regulations across the world make provision for labelling to ensure that consumers are fully informed whether foods or ingredients within them have been irradiated.
The IFST believes that more effort should be made to overcome the consumer reaction to the technology through publicity and educational campaign by professional bodies.
"Many consumers are initially hostile to irradiation but when the process is explained to them they become generally more in favour," the research body stated.
Many processing methods have been developed to help prevent food spoilage and improve safety. The traditional methods of preservation, such as drying, smoking and salting have been supplemented with pasteurisation, canning, refrigeration, freezing and chemical preservatives.
Food irradiation is the process of exposing food to a carefully controlled amount of energy in the form of high-speed particles or rays. The choice of irradiation method will depend on the material needing to be treated.
To treat the surface or a thin layer of a food, processors would usually choose beta particles. To treat a bulky product such as an entire sack of spices, one would choose gamma rays, a more powerful form of X-ray.
A World Health Organisation scientific report in 1992 found that irradiation posed no risk to human health.
"On the basis of the extensive scientific evidence reviewed, the report concludes that food irradiated to any dose appropriate to achieve the intended technological objective is both safe to consume and nutritionally adequate," the report stated. "The experts further conclude that no upper dose limit need be imposed, and that irradiated foods are deemed wholesome throughout the technologically useful dose range from below 10 kGy to envisioned doses above 10 kGy."
The US National Centre for Policy Analysis estimates that if half the food at greatest risk consumed in the country were to be irradiated, food-borne illnesses would decline by 900,000 cases annually and deaths by 352. The centre estimates irradiation would cost about five cents per pound for meat and poultry products.
The IFST is the independent professional qualifying body for food scientists and technologists.