title: Comparative analysis of three Australian finger lime (Citrus australasica) cultivars: identification of unique citrus chemotypes and new volatile molecules.
abstract: The volatile constituents of the peel of three cultivars of Australian finger lime (Citrus australasica) were investigated: Alstonville, Judy's Everbearing and Durham's Emerald. Both qualitative and quantitative GC-MS analyses were performed on their peel solvent extract. The results showed that the unique phenotypes of finger lime are also correlated to unique molecular compositions. Each cultivar revealed a different chemotype: limonene/sabinene for cv. Alstonville, limonene/citronellal/isomenthone for cv. Judy's Everbearing, and limonene/citronellal/ citronellol for cv. Durham's Emerald. To the best of our knowledge, these chemotypes have never been reported in any other citrus species. Furthermore, the amounts of some volatile constituents (γ-terpinene, α-pinene, β-pinene, citral), which are generally the major constituents besides limonene in lime species, were surprisingly low in the three cultivars. Comparative GC-MS analysis also showed that some volatile molecules tended to be specific to one cultivar and could therefore be considered as markers. Moreover six molecules were reported for the first time in a citrus extract and confirmed by synthesis. Heart-cutting enantioselective two-dimensional GC-MS was performed to determine the enantiomeric distribution of the major chiral constituents. The combined data on three finger lime cultivars gives evidence of their divergence from other citrus species.
authors.affiliation: Firmenich SA, Corporate R&D Division, Geneva, Switzerland. Electronic address: estelle.delort@firmenich.com.
authors.forename: Estelle
authors.initials: E
authors.lastname: Delort
authors.affiliation: Firmenich SA, Corporate R&D Division, Geneva, Switzerland.
authors.forename: Alain
authors.initials: A
authors.lastname: Jaquier
authors.affiliation: Firmenich SA, Corporate R&D Division, Geneva, Switzerland.
authors.forename: Erik
authors.initials: E
authors.lastname: Decorzant
authors.affiliation: Firmenich SA, Corporate R&D Division, Geneva, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Chapuis
authors.affiliation: Firmenich SA, Corporate R&D Division, Geneva, Switzerland.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Casilli
authors.affiliation: Firmenich SA, Corporate R&D Division, Geneva, Switzerland.
authors.forename: Eric
authors.initials: E
authors.lastname: Frérot
mesh_terms: D001315:Australia; D002957:Citrus / Q000737:chemistry* / Q000145:classification; D005638:Fruit / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D015394:Molecular Structure; D009812:Odorants / Q000032:analysis; D009822:Oils, Volatile / Q000032:analysis*; D010936:Plant Extracts / Q000737:chemistry*
chemical_list: D009822:Oils, Volatile; D010936:Plant Extracts
keywords: 1,2-Epoxy-p-methan-5-one; 1,2:5,6-Diepoxy-p-menthane; 2,3-Epoxy-p-menthan-6-one; 4-Hydroxy-6-isopropyl-3-methylcyclohex-2-enone; 6-Methyl-1-octylacetate; Alstonville; Citronellyl citronellate; Durham’s Emerald; Isoascaridole; Judy’s Everbearing; p-Menth-1-en-3-ol-6-one