Vol. 7, Issue 2 (2019)

Consumers expect that the food they eat must be safe. In addition, consumers also wants the food to have high nutritional value with minimal preparation times, as evidenced by the growth in products such as convenience ready to eat and minimally processed fresh produce. In order to meet these demands, food manufacturer are looking for new method and technologies. One such technology is irradiation. Irradiation is non-thermal food preservation technique which is used to extend and enhance the shelf life of fresh or processed foods. Food irradiation is an energy-efficient, non-chemical method of food processing that can help reduce those huge losses occurring due to spoilage or contamination by harmful bacteria and other parasitic life forms. It involves exposure of foods to ionizing radiations either pre-packaged or in bulk to reduce the risk of foodborne illness, delaying or eliminating sprouting or ripening. Gamma rays, electron beams, and x-rays are used for irradiation of foods. Properly treated, irradiated foods retain their fresh appearance, flavour, and nutritional value, while most foods can be pre-packaged before irradiation, reducing the risk of re-contamination. The inactivation mechanism involves two processes either direct or indirect method. Ionizing radiations kills microbes directly by damaging biomolecules of cells. When incoming photons hit the microbes or food molecules, collisions occur, as a result, the microbes die. Irradiation doses can be generated using Cobalt-60 as an radiation source. Electron beams are propelled out of an electron gun with streams of high-energy electrons. Electron beam accelerators are used in X-ray facility to target electrons on metal plate.

Exposure time depends upon the characteristics of food and the doses of irradiation. Irradiation dose is measured as gray (Gy). This is a measure of the amount of energy transferred to food, microbe or other substance being irradiated. The most commonly products used for irradiation are fresh fruits and vegetables (strawberry, mangoes, guava, tomato, potato, garlic etc, cereals and cereal products (wheat, rice, barley, flour etc).