Explain the Food Irradiation - method of food preservation?

Food irradiation is another sterilizing technique in which the foods are bombarded by high-energy rays called gamma rays or by fast-moving electrons to kill bacteria, fungi and insects and in some cases, to delay fruit ripening. It has been used in pasteurizing or sterilizing perishable foods such as meat, fish and fruits and extending their storage lives for long periods. It is also used for sprouting inhibition in onions, potatoes etc. Sterilization can be effected at room temperature and hence, the technique is also called as cold sterilization process. A major benefit of irradiation is that it can occur after the food is packaged and sealed. Cobalt-60 or Cesium-137 or electrons producing machines are the principal sources of ionizing radiations used for food irradiation. The unit of radiation is in terms of rads (and kilorad or megarad).