The ESR detection of irradiated food

Previous work has shown that the calcified tissues in several foods give rise to characteristic ESR spectra on irradiation. Further foods have now been examined. Mussel and crab shelss give large signals, compared with bones of poultry, beef or frog, while prawn cuticle gives a smaller signal. The limits of detection of irradiation vary between species but are blow the doses likely to be used commercially. Quantitative estimation of dose can be achieved by re-irradiation and extrapolation to zero signal.