Isolation and chemical characterization of laurel leaf oil

Effect of Different Locations on the Chemical Composition of Essential Oils of Laurel (Laurus nobilis L.) Leaves Growing Wild in Turkey

The essential oil components of Laurus nobilis gathered from seven different locations of Turkey were identified by gas chromatography/mass spectrometry. The oil yields on a dry weight basis ranged between 1.4% to 2.6%. The major component was 1,8-cineole (51.73-68.48%); other predominant components were alpha-terpinyl acetate (4.04-9.87%), sabinene (4.44-7.75%), alpha-pinene (2.93-4.89%), beta-pinene (2.58-3.91%), terpinene-4-ol (1.33-3.24%), and alpha-terpineol (0.95-3.05%). Minor qualitative and major quantitative variations of some compounds were determined with respect to localities of collection. As a result, the 1,8-cineole content of these oils was significantly higher than those of other constituents of L. nobilis. Laurel is usually considered as the natural source of this compound, used in the flavor and fragrance industry.

Effect of drying method on the volatiles in bay leaf (Laurus nobilis L.)

The effect of different drying treatments on the volatiles in bay leaf (Laurus nobilis L.) was studied. Simultaneous distillation extraction (SDE) and solid-phase microextraction (SPME) were compared by gas chromatography-mass spectrometry (GC-MS) of the volatile components in bay leaves. SDE yielded better quantitative analysis results. Four drying treatments were employed: air-drying at ambient temperature, oven-drying at 45 degrees C, freezing, and freeze-drying. Oven drying at 45 degrees C and air-drying at ambient temperature produced quite similar results and caused hardly any loss in volatiles as compared to the fresh herb, whereas freezing and freeze-drying brought about substantial losses in bay leaf aroma and led to increases in the concentration levels of certain components, e.g., eugenol, elemicin, spathulenol, and beta-eudesmol.

Essential oils from Azorean Laurus azorica

The essential oils isolated from leaves of ten and from unripe berries of eight populations of Laurus azorica (Seub.) Franco, collected on five islands of the Azorean archipelago, were analysed by GC and GC-MS. All oil samples were dominated by their monoterpene fraction (60-94%), alpha-pinene (15-37%) and 1,8-cineole (12-31%) being the main components of the leaf oils, while trans-beta-ocimene (27-45%) and alpha-pinene (12-22%) were the main components of the oils from the berries. The sesquiterpene fractions of the oils ranged from 3 to 17% and the main components were beta-caryophyllene (traces-8%) and beta-elemene (traces-3%) both in the leaf and berry oils. Some phenylpropanoid components were also present, in total amounting to 17%, trans-cinnamyl acetate (215% of the leaf oils) being the main component of this fraction. Cluster analysis of the enantiomeric composition of alpha- and beta-pinene in the oils from the leaves clearly showed two groups, one constituted by the two populations growing on the island S. Jorge, and the other constituted by the remaining populations.