Food irradiation is yet another method of preservation that involves the exposure of food to ionizing radiation using high-energy radiation with small wavelengths of approximately 200 nanometres or high-speed electron beams. The main radiation sources applied for food irradiation (are almost similar to microwaves but with higher wavelengths and energy).They include: Electron beams, Gamma-rays and X-rays. Food irradiation aims to extend the shelf life of a food and reduce its likelihood of spoilage.
Which foods can be irradiated?
Vegetables, fruits, meat, grains, shellfish, seasonings can be irradiated.
How food irradiation works
The food is exposed to ionizing radiation from either gamma rays, x-rays or electron beams. The rays from either of the radiation sources are directed to a food and the energy released from them disrupts any chemical bonds along their path. These rays destroy micro-organisms such as bacteria, moulds etc and even insects. Although, they do not destroy viruses.
In most cases, irradiated foods are required to be labelled. Usually, you may read phrases such as ‘treated by irradiation’, which are indicative that a food has been irradiated.
The benefits of food irradiation
- Reduces food spoilage -This method destroys some microorganisms e.g. bacteria and moulds that cause food spoilage.
- Extends the shelf life of food products-The preserved foods last for a longer period.
Limitations of food irradiation
- Some common foods such as eggs and dairy products cannot be irradiated due to the increased possibilities of their flavour and texture alterations.