However, this has not been the case with irradiation which, although approved for use with a variety of foods in many countries, is still very limited in terms of treating seafood.

In Europe there is a radiation facility in Belgium which treats shrimp and the US Food and Drug Administration (FDA) has approved the irradiation of shrimp and prawns, as well as crab, lobster and crayfish, to control food-borne pathogens and extend shelf-life.

Irradiation is the physical treatment of food with high-energy ionizing radiation. Usually this takes the form of gamma rays produced by the radioisotope cobalt 60. It is a cold process so there is virtually no alteration in the form of the food after treatment has been carried out.

During irradiation, the energy waves affect unwanted microorganisms but are not retained in the food being treated. Scientists say there is no nutrient loss at least when compared with a process such as canning.

The European Commission (EC) is at pains to point out that irradiation does not replace hygiene, health or good manufacturing practice. (One of the issues raised by opponents of irradiating foods is that the process will be used to mask the fact that products are past their best.)

Labelling
The EC also states that irradiated food, or food products containing irradiated ingredients, must be labelled as such. Since 1986, all irradiated products sold in the USA must carry the international symbol called a radura, which resembles a stylized flower.

The FDA requires that both the logo and statement ‘Treated with irradiation’ or ‘Treated by irradiation’ appear on packaged foods, bulk containers of unpackaged foods, on placards at the point of purchase (for fresh produce), and on invoices for irradiated ingredients and products sold to food processors.

The labelling of irradiated foods, or lack of it, is another bone of contention for opponents of the treatment. Some groups argue that the radura does not accurately reflect the treatment that has been carried out.

The fact that the EC states that food irradiation has nothing to do with radioactive contamination of food resulting from a spill or an accident, probably does nothing to persuade consumers that irradiated food does not glow in the night.

There has long been a powerful, vocal and largely successful campaign by consumer groups and others against food irradiation. A number of concerns have been raised about the process, but the main reason for opposition to it may be an emotional one. The word ‘radiation’ is seen as threatening because of its associations with nuclear weapons and disasters like Chernobyl.

Surveys show that consumers’ views could be changed if they were provided with accurate information about the benefits and given an opportunity to try irradiated products.

This is unlikely to happen, at least in Europe where most large supermarket chains consider there is so much consumer resistance to irradiated foods and so little demand that there is no point in developing the technology.