Analysis and characterization of aroma-active compounds of Schizandra chinensis (omija) leaves

Volatile components from leaves of Schizandra chinensis (omija), a native plant of Korea, were extracted by simultaneous distillation-extraction (SDE) and analyzed by gas chromatography-mass spectrometry (GC-MS) using two types of capillary column with different polarities (DB-5MS and DB-Wax). The GC-MS analysis of volatile compounds obtained by SDE revealed that germacrene D is the most abundant compound (22.6%) in omija leaves, followed by β-elemene (17.4%), (E)-2-hexenal (8.7%), and (E)-β-ocimene (7.2%). Aroma-active compounds were determined by gas chromatography-olfactometry (GC-O) using the aroma-extract-dilution analysis method. (E,Z)-2,6-Nonadienal (cucumber) was the most intense aroma-active compound due to its higher flavor-dilution factor (243-729) than any other compound. (Z)-3-Hexenal (green/apple), (E)-2-hexenal (green/fruity), and (E)-β-ocimene (wither green/grass) were also identified as important aroma-active compounds by GC-O. In addition, the volatile compounds were extracted by solid-phase microextraction (SPME), and the quantitative analysis of the SPME samples gave slightly different results, depending on the type of SPME fiber, compared with those from SDE, However, the aroma-active compounds identified in SPME were similar to those in SDE.