Application of Irradiation on Milk and Dairy Products

Abstract

Application of ionizing radiation treatment of foods on an industrial scale started in the early 1980s after the joint Food and Agriculture Organization/International Atomic Energy Agency (IAEA)/World Health Organization (WHO) expert committee accepted the application of a 10-kGy overall average dose for foods. Vast knowledge has now accumulated on the chemical and biological effects of ionizing irradiation, which has contributed to the promotion of its utilization. Irradiation is used as a food preservation method to destroy microorganisms and increase shelf life. The radiation dose unit, previously referred to as the rad, is currently known as the Gray (Gy). The Gy is the absorption of 1 J of energy per kilogram irradiated material and is equivalent to 100 rads. Irradiation doses usually range from 10 Gy to 1 kGy for sprouting inhibition of potatoes, onions, garlic, etc.; 1 to 10 kGy for fresh meat and seafood as well as vegetables and fruits; and 10 to 100 kGy mainly for food sterilization. The recommended dose levels are as follows: low level at 1 kGy to inhibit insect infestation and delay ripening; medium level at 1-10 kGy to reduce bacterial load (particularly of pathogens); and high level at 10-50 kGy for commercial sterilization and elimination of viruses. Irradiation of foodstuffs has an additional advantage: it can be used in prepackaged foodstuffs to avoid microbial recontamination, in addition to allowing the use of different packaging materials. © 2010 Elsevier Inc. All rights reserved.