Identification of Irradiation of Boned Chicken by Determination of o-Tyrosine and Electron Spin Resonance Spectrometry.

Ortho-tyrosine detection method is used for the detection of irradiated protein-rich foods. A new procedure determining o-tyrosine content was examined in regard to the identification of food having undergone ionization treatment. A new fluorometric HPLC method allows the detection of irradiated foods at 10 kGy. This method was compared with an electron spin resonance (ESR) method recommended by European countries for the detection of irradiated foods. The method is applied only those food samples that contain bone or cellulose. The dose response of o-tyrosine production was linearly increased upto 30 kGy. Chicken bones were dried in a desiccator, after which ESR signals were recorded in the samples. The dose response of the ESR signal was observed two weeks after irradiation, and the equation for curve fitting was a quadratic polynominal. The ESR signal intensity correlated with the logarithm of o-tyrosine production, a close relationship observed.