Volatile constituents of sicilian fenugreek (Trigonella foenum-graecum L.) seeds

The volatiles occurring in Sicilian fenugreek seeds were investigated. Headspace components, concentrated by solid phase microextraction (SPME), as well as those found in methanolic, aqueous and dichloromethane extracts were identified by GC/MS; a total of 175 components were detected, 66 of them were identified for the first time in fenugreek seeds. Headspace analysis shows prominent presence of carbonyl compounds (hexanal, 2-methyl-2-butenal, 3-octen-2-one, trans-cis- and trans-trans-3,5-octadien-2-one), of sesquiterpene hydrocarbons such as delta-elemene, gamma-cadinene and alpha-muurolene, alcohols (pentanol, hexanol, 2-methyl-2-buten-1-ol, 1-octen-3-ol), heterocycle compounds such as 3-hydroxy-4,5-dimethyl-2(5H)-furanone (sotolon), dihydro-5-pentyl-2(3H)-furanone (gamma-nonalactone), dihydro-5-ethyl-2(3H)-furanone (gamma-caprolactone) and other furan compounds, particularly involved in the aroma. Methanolic extract, as well as aqueous and dichloromethane extracts, show the presence of higher boiling point compounds such as C.-Cl. saturated acids and long chain unsatured acids such as oleic, linoleic and linolenic; two isomers of 3-amino-4,5-dimethyl-3,4-dihydro-2(5H)-furanone, precursor of sotolon, were found in all the extracts, along with an unidentified sesquiterpenol.