Aroma-active compounds of Elsholtzia splendens using AEDA and HS-SPME-GC-O dilution analysis

This study was conducted to determine the composition of essential oil and headspace from Elsholtzia splendens, and to determine the aroma-active compounds of this aromatic plant. Eighty-five components were identified in the oil by GC and GC-MS. The major compounds were naginata ketone (70.43%) and elsholtzia ketone (4.95%). Sixty-eight volatile flavour constituents were detected in the headspace of this herb, and geranyl acetate (4.48%) was the most abundant component. Flavour dilution (FD) factors were evaluated by aroma extract dilution analysis with gas chromatography-olfactometry (GC-O). Naginata ketone, alpha-pinene, elsholtzia ketone, carvone oxide and geraniol showed high FD-factors (>= 5). Naginata ketone, geraniol, elsholtzia ketone, carvone oxide and geranyl acetate were regarded as the characteristic odour components of the essential oil by the sniffing test. Especially, naginata ketone and geraniol were considered as most similar odour components to Elsholtzia splendens by organoleptic evaluation with GC-O. Naginata ketone, nerol, geraniol and carvone oxide were considered as having a Elsholtzia splendens-like odour by headspace solid-phase microextraction GC-O (HS-SPME-GC-O) dilution analysis. Naginata ketone was the most intensive compound in HP-SPME-GC-O dilution analysis by varying the fibre length, and naginata ketone and geraniol were the aroma-active compounds in HS-SPME-GC-O dilution analysis by varying the GC split ratio. Copyright (C) 2008 John Wiley & Sons, Ltd.