Detection of Irradiated Food Using 2-Alkylcyclobutanones as Markers: Verification of the European Committee Standardization Method EN1785 for the Detection of Irradiated Food Containing Lipids

Abstract

῍ Corresponding author 2-Alkylcyclobutanones (ACBs) are specific radiolytic products in irradiated lipid-containing food and can be used to detect irradiation of foodstu#s. EN1785, a European Committee Standardization Method, can detect 2-dodecylcyclobutanone (DCB) and 2-tetradecylcyclobutanone (TCB), which are ACBs, using GC/MS, thereby allowing judgement as to whether foodstu#s have been irradiated. In this study, the performance of EN1785 as a qualitative test in a single laboratory was evaluated and its applicability to beef, pork, chicken and salmon was verified. In the performance evaluation test, lipids extracted from unirradiated food using the Soxhlet extraction method were used as negative samples. Further, negative samples, to which DCB and TCB were added at 0.05 ῌg/g lipid (equivalent to the amount generated in food when irradiated at 0.5 kGy or more), were used as positive samples. For each food type examined, 4 negative and 16 positive samples were analyzed by EN1785 to verify the method's ability to detect irradiation. All of the negative samples were judged negative and all of the positive samples were judged positive. Thus, the method should be able to detect irradiation in beef, pork chicken and salmon irradiated at 0.5 kGy or higher. Next, to confirm that this is the case, the same types of food examined above, both unirradiated and irradiated at doses of 0.5ῌ4 kGy, were analyzed by the method. All of the unirradiated samples were judged negative and all of the irradiated samples were judged positive. In a laboratory di#erent from the one where the aforementioned evaluation was conducted, a performance evaluation test was carried out. Blind coded samples, including unirradiated and irradiated samples, were then analyzed in the laboratory according to EN178S. Ten samples (2 unirradiated and 8 irradiated samples) were analyzed for each type of food and the verified method was found to be 100ῌ accurate. Even after the irradiated foodstu#s had been frozen for 6ῌ9 months, it was still possible to judge whether the foodstu#s had been irradiated or not using the EN1785 method.

Liquid Chromatography–Electrospray Ionization Tandem Mass Spectrometric Analysis of 2-Alkylcyclobutanones in Irradiated Chicken by Precolumn Derivatization with Hydroxylamine

“…The molar ratio of 2-DCB to 2-TCB as determined in this study was 2.3:1, which is consistent with the results obtained by Elliott et al (2.1:1) . The higher radiation yield of 2-DCB than that of 2-TCB is in line with the higher concentration of their corresponding precursor fatty acids (i.e., palmitic acid and stearic acid) in chicken samples. , These results suggest that our method is suitable for the determination of radiation induced 2-ACBs in irradiated food.…”