title: Chemometric Tools to Highlight the Variability of the Chemical Composition and Yield of Lebanese Origanum syriacum L. Essential Oil.
abstract: This study deals with the variation in the yield and composition of Lebanese Origanum syriacum L. essential oil (EO) according to harvesting time, drying methods used, and geographical location. Plant material was harvested twice a month all over 2013 and 2014 from Qartaba and Achkout located at high altitude and from Byblos at low altitude. EOs of the aerial parts were obtained by hydrodistillation. The highest yields were obtained at full flowering stage and slightly reduced after flowering. The GC/MS analysis revealed the presence of 50 components representing 90.49 - 99.82%, 88.79 - 100%, and 95.28 - 100% of the total oil extracted from plants harvested from Qartaba, Achkout, and Byblos, respectively. The major components in the oils were: carvacrol (2.1 - 79.8%), thymol (0.3 - 83.7%), p-cymene (2.8 - 43.8%), thymoquinone (0.4 - 27.7%), γ-terpinene (0.4 - 10.0%), octan-3-ol (0.3 - 4.9%), caryophyllene oxide (0.2 - 4.7%), oct-1-en-3-ol (0.3 - 3.7%), β-caryophyllene (0.7 - 3.2%), cis-sabinene hydrate (0.1 - 2.8%), terpinen-4-ol (0.1 - 2.8%), and α-terpinene (0.2 - 2.2%). Independent components analysis (ICA) revealed that two groups were discriminated, reflecting compositional differences in the EOs profiles of the Lebanese oregano samples: O. syriacum grown in Qartaba and Achkout belongs to carvacrol chemotype, while O. syriacum grown in Byblos belongs to thymol chemotype. The flowering phase was the most productive period in terms of yield, bringing marked changes in the EO composition by increasing the amounts of carvacrol or thymol, and decreasing those of thymoquinone and p-cymene.
authors.affiliation: Faculty of Agricultural and Food Sciences, Holy Spirit University of Kaslik, B.P. 446, Jounieh, Lebanon.|Institut Jean-Pierre Bourgin INRA, AgroParisTech, RD 10, Route de Saint-Cyr, Versailles, France.
authors.forename: Raviella
authors.initials: R
authors.lastname: Zgheib
authors.affiliation: Institut Jean-Pierre Bourgin INRA, AgroParisTech, RD 10, Route de Saint-Cyr, Versailles, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Chaillou
authors.affiliation: Faculty of Agricultural and Food Sciences, Holy Spirit University of Kaslik, B.P. 446, Jounieh, Lebanon.
authors.forename: Naim
authors.initials: N
authors.lastname: Ouaini
authors.affiliation: Department of Chemistry and Biochemistry, Faculty of Sciences II, Lebanese University, 90656, Jdeideth El Matn, Fanar, Lebanon.
authors.forename: Amine
authors.initials: A
authors.lastname: Kassouf
authors.affiliation: UMR1145 Ingénierie Procédés Aliments, AgroParisTech, 16 rue Claude Bernard, FR-75005, Paris.|UMR1145 Ingénierie Procédés Aliments, INRA, 16 rue Claude Bernard, FR-75005, Paris.
authors.forename: Douglas
authors.initials: D
authors.lastname: Rutledge
authors.affiliation: Faculty of Agricultural and Food Sciences, Holy Spirit University of Kaslik, B.P. 446, Jounieh, Lebanon.
authors.forename: Desiree
authors.initials: D
authors.lastname: El Azzi
authors.affiliation: Faculty of Agricultural and Food Sciences, Holy Spirit University of Kaslik, B.P. 446, Jounieh, Lebanon. marcelbeyrouthy@usek.edu.lb.
authors.forename: Marc
authors.initials: M
authors.lastname: El Beyrouthy
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry; D009822:Oils, Volatile / Q000737:chemistry* / Q000302:isolation & purification; D031341:Origanum / Q000737:chemistry*
chemical_list: D009822:Oils, Volatile
keywords: 
  Origanum syriacum
  ; Essential oils; Geographical location; Harvest date; Independent components analysis