عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Ortho- tyrosine detection method can be used for detection of irradiated protein rich foods. Tyrosine isomers produced by gamma radiation of aqueous phenylalanine solutions at wide dose levels (0.1-50kGy) were examined to obtain basic information for o-tyrosine detection method of irradiated foods. Determination of tyrosines produced in aqueous phenylalanine solutions were carried out by high performance liquid chromatography and fluorescence detection. The detection limit of o-tyrosine was 0.01ppm and the linear range of calibration and the relative standard deviation of analysis was 50 ng and 4-13%, respectively. The amounts of the tyrosines increased with the irradiation level up to 10kGy and no further tyrosine formation was observed when the dose level was increased. At a constant dose level, the yield of tyrosines initially increased with the phenylalanine concentration, while with further increase of phenylalanine concentration no effect on increase of tyrosine yield was observed. When the dose rate was varying from 2.3kGy/h to 1.2kGy/h with a total amount of 10kGy in each case, there was no significant effect on tyrosine isomers formation was observed. Also the results showed that tyrosine yield was affected by temperature, pH and the presence of oxygen.