Food irradiation

This is a process which uses radiation such as gamma rays or X-rays to kill bacteria within food which are responsible for food poisoning.

This includes campylobacter, salmonella, e coli and listeria bacteria.

This process is also used in the growing of food in particular to delay the ripening or sprouting of certain foods. It can also slow down the process of deterioration.

How does food irradiation work?

Food is exposed to ‘ionising radiation’ which has the same effect on it as cooking or any other type of heat treatment but with less drastic effects on the taste or the texture.

(Ionising radiation is a type of radiation in which electromagnetic waves convert atoms to ions – by adding or removing electrons). Gamma rays and x-rays are examples of ionising radiation.

Food which is exposed to this radiation also absorbs energy which results in the production of molecules known as ‘free radicals’. These molecules kill any micro organism which includes bacteria, viruses and parasites.

This is seen as an effective way of killing harmful bacteria without damaging the taste, smell or texture of food. This food only absorbs low levels of energy so there are only small changes to its taste or texture. These chemical changes are similar to those which occur when food is cooked, put in tins or undergoes pasteurisation. They are safe to eat and pose no risk to health.

The only source of ionising radiation - for food irradiation - within the UK is gamma rays.

Finding out about food irradiation

Many foods contain this information on their labelling. If they or their ingredients have undergone irradiation then this will be listed as ‘irradiated food’ or something similar.

This equally applies to food purchased in cafes and restaurants which is meant to be eaten right away. This information must be shown on a menu, ticket or a sign within the premises so that customers can see this before they purchase the food.

Examples of irradiated foods

There are 7 categories of irradiated foods in the UK which include:

• Poultry
• Fish and shellfish
• Cereals
• Fruit
• Vegetables
• Tubers and bulbs
• Condiments and spices

However, under current regulations these are allowed to be irradiated but only a single licence has been approved to date and that is for a number of herbs and spices.

(Source: Food Standards Agency)

This process takes places in authorised premises which are subject to inspection and regulation by the Food Standards Agency. It is viewed as a matter of personal choice on the part of the consumer rather than an issue of safety.

This process helps to increase its shelf life as well as killing any bacteria which means that irradiated food is safe to eat.