The identification of irradiated seasoned filefish (Thamnaconus modestus) by different analytical methods

Dried seasoned filefish (Thamnaconus modestus) was irradiated at 0-10 kGy and the identification of irradiation treatment was investigated by analyzing the characteristics of thermoluminescence (TL), hydrocarbon (HC), and 2-alkylacyclobutanone (2-ACB). The TL (TL1), glow curve of the irradiated samples peaked at approximately 150 °C with high intensity, but that of the non-irradiated samples peaked at about 300 °C with little intensity, thus making it possible to discriminate between irradiated and non-irradiated samples. Moreover, TL ratio (TL1/TL2), through normalization steps, enhanced the reliability of the TL1 results. Six kinds of HCs and three kinds of 2-ACBs quantitatively determined for the samples linearly increased in proportion to irradiation doses. In particular, two HCs like 1-hexadecane and 1,7-hexadecadine, and three ACBs, such as 2-dodecylcyclobutanone, 2-(5′-tetradeceyl)cyclobutanone, and 2-tetradecylcyclobutanone, were identified only in the irradiated samples as radiation-induced markers.