Sterilising bee products to destroy pathogens using radiation

Radiation generally does not alter physiochemical properties of nutrients (Yook et al., 1998) when the appropriate dosage (i.e. treatment intensity and length) is provided (Undeen and Vander Meer, 1990). Greater than 2 kGy of gamma radiation from cobalt60 destroyed N. apis spores (Katznelson and Robb, 1962), 500 Gy gamma radiation from a caesium137 irradiator damaged developmental stages of N. apis (Liu et al., 1990), and 10 kGy of high velocity electron-beam radiation effectively sterilised spores of the bacteria Paenibacillus larvae and the fungus Ascophaera apis, responsible for American foulbrood and chalkbrood disease, respectively (Melathopoulos et al., 2004). Although 3.8 J/cm2 of 254 nm ultraviolet radiation can reduce viability of Nosema algerae spores from moths (Undeen and Vander Meer, 1990), it can also degrade nutrients such as fatty acids (Yook et al., 1998) and may not kill all organisms because the entire food stuff was not penetrated.

For pathogen control, the United States Department of Agriculture currently permits a number of fresh or frozen foods destined for human consumption to be irradiated up to a maximum of 5.5 kGy; dried food may be irradiated up to 30 kGy (USDA, 2008).