Characterization of volatiles and aroma-active compounds in honeybush (Cyclopia subternata) by GC-MS and GC-O analysis

Date
2012-03
Authors
Le Roux, Maritha.
Cronje, J. Christel
Burger, B. V.
Joubert, Elizabeth
Journal Title
Journal ISSN
Volume Title
Publisher
American Chemical Society
Abstract
Volatile organic compounds (VOCs) in fermented honeybush, Cyclopia subternata, were sampled by means of a high-capacity headspace sample enrichment probe (SEP) and analyzed by gas chromatography-mass spectrometry (GC-MS). Stereochemistry was determined by means of enantioselective GC-MS with derivatized β-cyclodextrin columns as chiral selectors. A total of 183 compounds, the majority of which are terpenoids (103; 56%), were identified by comparing their mass spectra and retention indices with those of reference compounds or tentatively identified by comparison with spectral library or literature data. Of these compounds, 37 were determined by gas chromatography-olfactometry (GC-O), using detection frequency (DF) and aroma extract dilution analysis (AEDA), to be odor-active (FD ≥ 2). (E)-β-Damascenone, (R/S)-linalool, (E)-β-damascone, geraniol, (E)-β-ionone, and (7E)-megastigma-5,7,9-trien-4-one were identified with the highest FD factors (≥512). The odors of certain compounds, that is, (6E,8Z)-megastigma-4,6,8-trien-3-one, (6E,8E)-megastigma-4,6,8-trien-3-one, (7E)-megastigma-5,7,9-trien-4-one, 10-epi-γ-eudesmol, epi-α- muurolol, and epi-α-cadinol, were perceived by GC-O assessors as typically honeybush-like. © 2012 American Chemical Society.
Description
The original publication is available at http://pubs.acs.org/doi/full/10.1021/jf2048383
Keywords
Gas chromatography-mass spectrometry (GC-MS), Gas chromatography-olfactometry (GC-O), Honeybush tea -- Processing, Odor-active compounds, Sample enrichment probe, Terpenoids, Volatile organic compounds
Citation
Le Roux, M., Cronje, J. C., Burger, B. V. & Joubert, E. 2012. Characterization of volatiles and aroma-active compounds in honeybush (Cyclopia subternata) by GC-MS and GC-O analysis, Journal of agricultural and food chemistry, 60(10):2657-2644, doi:10.1021/jf2048383.