Food irradiation is one of the most common food preservation methods and is used on a global scale. The ability to identify irradiated food is important for assuring compliance with regulatory policies, such as food labeling requirements, and for informed consumer choice. There is thus a significant demand for analytical methods of high sensitivity and selectivity to identify irradiated food, especially for foods subjected to low-dose irradiation and for processed or composite foods that contain small quantities of irradiated ingredients. 2-Alkylcyclobutanones(2-ACBs) are uniquely formed during food irradiation and have been adopted by the European Committee for Standardization as signature biomarkers for the identification of irradiated foods. We now report the development of a...[ Read more ]

Food irradiation is one of the most common food preservation methods and is used on a global scale. The ability to identify irradiated food is important for assuring compliance with regulatory policies, such as food labeling requirements, and for informed consumer choice. There is thus a significant demand for analytical methods of high sensitivity and selectivity to identify irradiated food, especially for foods subjected to low-dose irradiation and for processed or composite foods that contain small quantities of irradiated ingredients. 2-Alkylcyclobutanones(2-ACBs) are uniquely formed during food irradiation and have been adopted by the European Committee for Standardization as signature biomarkers for the identification of irradiated foods. We now report the development of a novel assayfor quantification of 2-ACBs in γ-irradiated food by liquid extraction of fat content followed by pre-column derivatization and liquid chromatography-tandem mass spectrometric (LC-MS/MS) detection. Pre-column derivatization with hydroxylamine introduced a polar functional group into the otherwise non-polar 2-ACBs, which greatly enhanced Electrospray IonizationMass Spectrometry (ESI-MS) response. The method was validated for extraction efficiency, precision, accuracy, and detection limit. In comparison with the current European official method (EN1785:2003) for 2-ACBs determination, our new LC-MS/MS method offers a more efficient sample processing protocol with reduced solvent consumption. More importantly, the combination of chemical derivatization and LC-MS/MS detection significantly enhanced the analytical sensitivity of the method, which allows confident identification of food irradiated with as little as 10 Gy.