Analysis of 2-Alkylcyclobutanones in Cashew Nut, Nutmeg, Apricot Kernel, and Pine Nut Samples: Re-evaluating the Uniqueness of 2-Alkylcyclobutanones for Irradiated Food Identification

摘要

2-Alkylcyclobutanones (2-ACBs) have long been considered as unique radiolytic products that can be used as indicators for irradiated food identification. A recent report on the natural existence of 2-ACB in non-irradiated nutmeg and cashew nut samples aroused worldwide concern because it contradicts the general belief that 2-ACBs are specific to irradiated food. The goal of this study is to test the natural existence of 2-ACBs in nut samples using our newly developed liquid chromatography—tandem mass spectrometry (LC—MS/MS) method with enhanced analytical sensitivity and selectivity (Ye, Y.; Liu, H.; Horvatovich, P.; Chan, W. Liquid chromatography—electrospray ionization tandem mass spectrometric analysis of 2-alkylcyclobutanones in irradiated chicken by precolumn derealization with hydroxylamine. /. Agric. Food Chem. 2013, 61, 5758—5763). The validated method was applied to identify 2-dodecylcyclobutanone (2-DCB) and 2-tetradecylcyclobutanone (2-TCB) in nutmeg, cashew nut, pine nut, and apricot kernel samples (n = 22) of different origins. Our study reveals that 2-DCB and 2-TCB either do not exist naturally or exist at concentrations below the detection limit of the existing method. Thus, 2-DCB and 2-TCB are still valid to be used as biomarkers for identifying iradiated food.