What’s wrong with food irradiation?

Irradiation uses ionising radiation, which alters food’s molecular structure, but leaves it looking the  intact.  Substances produced by exposure to radiation are known as radiolytic products. Their presence indicates whether or not a product been irradiated (Chauwan, S. et al. (2008). Detection methods for irradiated food. Comprehensive Reviews in Food Science and Food  Safety, http://onlinelibrary.wiley.com/doi/10.1111/j.1541-4337.2008.00063.x/full).

Different foods react differently to  radiation. The changes in them mean that Irradiated produce is processed; it is no longer fresh.