Thermoluminescence detection of Korean traditional foods exposed to gamma and electron-beam irradiation

Thermoluminescence(TL) analysis was applied to detect irradiated Korean traditional condiments and soup mixes containing salt(NaCl). These food items, which are commercially irradiated in Korea, showed a consistently high correlation(R²) between the absorbed doses and the corresponding TL responses. It was proved that table salt played a role as an in-built indicator in TL measurements and its concentration in test samples was proposed as a correction factor for varying conditions of TL measurements. Pre-established threshold values were successfully adopted to identify 167 coded samples of Ramen soup mixes, both non-irradiated and irradiated with gamma and electron-beam energy. The TL intensity of irradiated soup mixes decreased with the lapse of time, but was still distinguishable from that of the non-irradiated samples at the fourth month of ambient storage. Expected estimates of absorbed doses, 2.85 and 4.75 kGv were obtained using a quadratic equation with average values of 1.57 and 4.90 kGy, respectively.