Identification of 2-alkylcyclobutanones in nutmeg (Myristica fragrans)

The natural existence of the irradiation markers, namely, 2-decylcyclobutanone (2-DCB) and 2-dodecylcyclobutanone (2-dDCB), in nutmeg (Myristica fragrans) has recently been reported. In this study, 2-DCB and 2-dDCB were extracted from nutmeg of five different origins using supercritical fluid extraction (SFE). A 50-kGy irradiated sample was used to optimise the parameters of SFE and solid-phase extraction. The irradiated samples were analysed by gas chromatography–mass spectrometry, whereas the non-irradiated samples were analysed with high-resolution gas chromatography–mass spectrometry. Both 2-DCB and 2-dDCB were detected and identified in the irradiated samples at 5 kGy or greater. However, neither was present in the non-irradiated samples. Moreover, although the concentrations of 2-DCB and 2-dDCB were significantly reduced, a positive identification was obtained in irradiated nutmeg even after 30 weeks of storage.