Irradiation of food uses a specific form of Chromium to kill bacteria on those foods. It is able to reach places on the food that other preservation methods are unable to.

Produce is one of the food types that is often irradiated. The salad vegetables sold in bags are required to have a specific drop in bacteria levels and are usually put through a water and chlorine wash to try achieve this. The problem is that due to the structure of these vegetables, there are places that are not esily reached by the wash. Due to the nature of irradiation, these areas are addressed.

It is important to realise that irradiation does not make the food radioactive or harmful but has many consumers scared of the process and it's potential implications. It also does not have the negative impact on nutrients that heating preservative methods do (eg; pasteurisation).

If it were possible to reduce the amount of irradiation required to achieve the required kill rate, this would be a massive advantage in the promotion of this preservation method.

A team from Texas A & M University have developed methods that significantly reduce the amount of irradiation required and still achieves the required kill rate of bacteria on produce.

The first is using spices and other natural antimicrobial materials to reduce the amount of overall irration required.

The second involves filling the salad bag with oxygen or a nitrogen / oxygen  mix and then irradiating it with a lose dose. A chemical reaction occurs and the oxygen converts to ozone. This has antimicrobial propoerties and allows for the use of less irradiation than in conventional irradiation .

Although some people are concerned about ozone and potential health effects, it is a recognised antimicrobial agent and in the salad bags quickly converts back to oxygen and therefore has no harmful effects.

There is more research to be done but this has promising implications in making this useful preservation method more acceptable to the general public.