Essential oil composition of commercial black tea (Camellia sinensis)

The essential oil components of different tea brands were investigated by gas chromatography. The oil yields of dried tea samples were ranged from 0.09% to 0.63%. Twenty-five compounds from Supreme and Lipton Yellow Label tea brands representing 98.0% and 88.0% of the Camellia sinensis oil were identified, respectively. The main ones were β-pinene (51.2%) and α-pinene (30.2%). Nineteen components from Tapal tea brand representing 76.7% of the C. sinensis oil were determined with high contents of muurol-5-en-4-a-ol (10.5%) and muurol-5-en-4-b-ol (31.3%). Fifteen components from Deer and Diana tea brands were identified, accounting for 83.3% and 78.2% of the oil containing α-cadinol and β-pinene. Seventeen components from non-branded teas were determined with high contents of muurol-5-en-4-a-ol and muurol-5-en-4-b-ol. Twenty-one compounds from non-branded Bangladeshi Shezan and Indian teas were also identified. All oils consisted of monoterpenic hydrocarbons, oxygenated monoterpenes and sesquiterpenes.     

Essential oil composition of Turkish mountain tea (Sideritis spp.)

The essential oil components of aerial parts from Sideritis bilgerana, Sideritis tmolea and Sideritis congesta were investigated by GC and GC–MS. The oil yields of dried plants obtained by hydro-distillation were 0.26, 0.33 and 0.83 (v/w), respectively. Fifty compounds representing 94.6% of the S. bilgerana oil were identified. The main ones were β-pinene (51.2%) and α-pinene (30.2%). Thirty-six components, representing 79.7% of the S. congesta oil were determined with high contents of muurol-5-en-4-a-ol (11.7%) and muurol-5-en-4-b-ol (33.0%). Fourty-four components were identified accounting for 89.6% of the S. tmolea oil. Major constituents were α-cadinol (21.9%), β-caryophylene (10.6%), calamenene (7.05%), muurrol-5-en-4-b-ol (7.05%) and α-pinene (5.1%). All oils consist of monoterpenic hydrocarbons, oxygenated monoterpenes and sesquiterpenes. Muurol-5-en-4a-ol and muurol-5-en-4b-ol, at high percentages, were distinct components of S. congesta.     

圆角桉叶精油的化学成分(英文)

采用水蒸汽蒸馏法提取圆角桉叶精油,通过气相色谱-质谱(GC-MS)联用法分析鉴定两者的化学成分及质量分数。圆角桉叶精油共鉴定出51种化合物,占总离子流出峰面积的96.17%,主要成分为1,8-桉叶油素(28.46%),其后是β-蒎烯(12.21%)、α-蒎烯(11.00%)、蓝桉醇(7.27%)、α-松油醇(6.59%)、柠烯(5.34%)、香树烯(3.92%)、4-松油烯醇2.08%)、表蓝桉醇(1.77%)。     

Comparative evaluation of the antibacterial activities of the essential oils of Rosmarinus officinalis L. obtained by hydrodistillation and solvent free microwave extraction methods

Rosmarinus officinalis L. is a perennial herb that belongs to the Lamiaceae family. It is used as a food flavouring agent, and well known medicinally for its powerful antimutagenic, antibacterial and chemopreventive properties. Essential oils were obtained from this plant by hydrodistillation (HD) and solvent free microwave extraction (SFME). GC–MS analyses of the oils revealed the presence of 24 and 21 compounds in the essential oils obtained through HD and SFME, respectively. The total yield of the volatile fractions obtained through HD and SFME was 0.31% and 0.39%, respectively. Higher amounts of oxygenated monoterpenes such as borneol, camphor, terpene-4-ol, linalool, α-terpeneol (28.6%) were present in the oil of SFME in comparison with HD (26.98%). However, HD oil contained more monoterpene hydrocarbons such as α-pinene, camphene, β-pinene, myrcene, α-phellanderene, 1,8-cineole, trans β-ocimene, γ-terpenene, and cis sabinene hydrate (32.95%) than SFME extracted oil (25.77%). The essential oils obtained using the two methods of extraction were active against all the bacteria tested at a concentration of 10 mg ml⁻¹. Minimum inhibitory concentration (MIC) values for all the susceptible bacteria ranged between 0.23 mg ml⁻¹ and 7.5 mg ml^−1.     

Quantitative analysis of α-pinene and β-myrcene in mastic gum oil using FT-Raman spectroscopy

α-Pinene and β-myrcene are compounds that are contained in mastic gum in high concentrations. The β-myrcene percentage determines the marketability of mastic gums. The chemical composition of mastic gum oil of a representative resin quality was evaluated by gas chromatography–mass spectrometry (GC–MS) technique. FT-Raman spectroscopy, based on band intensity measurements, was used for the determination of α-pinene and β-myrcene content in mastic gum. Bands at 1658 and 1633 cm⁻¹ were used for the calibration of α-pinene and β-myrcene, respectively. Calibration curves were linear (correlation coefficient for α-pinene was 0.992 and 0.997 for β-myrcene) in the range 30–80 and 3–45%, respectively. Normalization of calibration curves, against the 802 cm⁻¹ cyclohexane band, minimized the effect of laser beam power fluctuations. The proposed method is rapid and simple. Accordingly, mastic gum oils from Chios island (Greece) contained 38.1–69.5% α-pinene and 4.5–57.9% β-myrcene.     

Chemical composition and antimicrobial activity of essential oil of Tarchonanthus camphoratus

The essential oil of Tarchonanthus camphoratus (Asteraceae), obtained by hydro-distillation, was analysed by gas chromatography–mass spectrometry (GC–MS) and also evaluated for antimicrobial activity. Out of 45 peaks representing 99.8% of the oil, 38 components which constitute 95.8% of the total oil were identified. The oil was dominated by monoterpenes, which accounted for 80.9% of the oil. This study indicates the presence of a high percentage of oxygenated monoterpenes (62.3%), of which the main constituents were fenchol (15.9%), 1,8-cineole (14.3%) and α-terpineol (13.2%). Other monoterpenes present in fairly good amounts were α-pinene (6.87%), trans-pinene hydrate (6.51%), terpinen-4-ol (4.74%) and camphene (3.76%). The oil was screened for antimicrobial activity against both Gram positive (Staphylococcus aureus, Bacillus ssp.) and Gram negative (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Klebsiella pneumoniae, Proteus mirabilis) bacteria and a pathogenic fungus Candida albicans. Except for P. aeruginosa, which showed resistance, the oil had pronounced antibacterial and antifungal activities.     

基于GC-MS和GC-O联用法分析佛手精油关键香气成分

研究佛手精油的挥发性物质和关键香气成分。佛手经水蒸气蒸馏法提取精油,利用气相色谱-质谱(gas chromatography-mass spectrometer,GC-MS)结合气相色谱-嗅闻(gas chromatography-olfactometry,GC-O)技术对挥发性物质和香气成分进行分析。GC-MS-O检测出36种挥发性物质,主要成分为D-柠檬烯(34.69%)、γ-松油烯(20.42%)、β-甜没药烯(4.59%)。采用稀释法和强度法分析发现D-α-蒎烯、D-柠檬烯、β-芳樟醇、别罗勒烯、4-松油醇、α-佛手柑烯具有较大的香气强度;D-α-蒎烯、β-蒎烯、β-罗勒烯、橙花乙酸酯、α-佛手柑烯具有较大风味稀释因子。综合分析认为D-α-蒎烯和α-佛手柑烯是佛手精油的关键特征香味成分。     

Essential oil composition of the turpentine tree (Pistacia terebinthus L.) fruits growing wild in Turkey

Constituents of essential oils from fruit samples of the turpentine tree (Pistacia terebinthus L.) collected from fifteen different localities of Turkey on August 2001 were identified by GC–MS. Twenty-eight compounds representing 92.3–100.0% of turpentine fruit oils were identified. The oil yields varied between 0.06% and 0.16%. The highest yield of oil was obtained from fruits of Antalya origin (Akba?-Serik) (0.16%). α-Pinene (51.3%), limonene (39.0%), p-cymen-8-ol (40.0%) and caryophyllene oxide (51.0%) were found as major components for different localities in Turkey. The predominant constituents in most samples were α-pinene (9.5–51.3%), limonene (tr-39.0%) and caryophyllene oxide (tr-51.5). Except for one collection (Manavgat-Antalya), which contained spathulenol (20.7%) and p-cymen-8-ol (40.0%), all the other samples yielded oils rich in α-pinene and limonene. β-Caryophyllene oxide is the most abundant compound in Hisarönü (?zmir), Alanya (Antalya) and Yaylada? (Hatay) oils. Results confirm the effect of locality on the oil content and composition.     

Chemical Composition and Antimicrobial Activity of Essential Oil of Matricaria recutita

Matricaria recutita is a herbaceous plant belonging to the Asteraceae family. The present study reports the chemical composition and antimicrobial activity of M. recutita essential oil and its main compounds. The essential oil was obtained from the aerial parts of the M. recutita by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The major components were α-bisabolol oxide (38%), followed by camphene (9.11%), sabinene (4.87%), limonene (6%),1,8-cineole (7.12%), camphor (6.54%), and α-pinene (6%). Essential oil of chamomile was evaluated for its antibacterial activities against three gram-positive and four gram-negative pathogenic bacteria. The essential oil and its main compounds were particularly active against Bacillus cereus, with the lowest minimum inhibitory concentration and minimum bactericidal concentration value (0.022 and 1.5 μg /mL). In conclusion, these results support the use of the essential oil and its main compounds for their antimicrobial properties.     

The antimicrobial activity of hydrophobic essential oil constituents acting alone or in combined processes of food preservation

This work evaluates the antimicrobial activity of widespread hydrophobic essential oil (EO) constituents, 3 hydrocarbon monoterpenes (α-pinene, β-pinene, and p-cymene) and 8 oxygenated monoterpenes (thymol, carvacrol, borneol, linalool, terpineol-4-ol, 1,8-cineole, α-terpinyl acetate, and camphor), as a function of the treatment medium pH, and possible synergistic effects in combination with mild heat or pulsed electric fields (PEF) treatments. Results obtained using the disk diffusion technique highlight phenols and alcohols as the best growth inhibitors and discount hydrocarbons due to their poorer activity. However, the evaluation of the bactericidal effect at pH 4.0 shows that most compounds assayed, including some hydrocarbons, were very effective against Escherichia coli and Listeria monocytogenes. Most EO constituents caused membrane permeabilization and sublethal injuries within survivors. Outstanding synergistic lethal effects were shown using mild heat (54 °C/10 min) or PEF (30 kV/cm/25 pulses) combined with 0.2 μl/ml of some antimicrobials, achieving 5 log₁₀ cycles of cell inactivation as a function of the treatment conditions. In most cases, combined treatments were more effective in apple than in orange juice.

Industrial relevance

The efficacy of EO constituents improves when combining with mild heat or PEF treatments, which allows us to propose very low doses of antimicrobials. The valuable synergistic effects observed offer the potential to improve traditional heat treatments by reducing treatment intensity and consequently adverse effects on food quality, and to enhance novel PEF treatments by achieving a higher degree of microbial inactivation.     

Volatile Constituents of Jambolan (<Emphasis Type="Italic">Syzygium cumini</Emphasis> L.) Fruits at Three Maturation Stages and Optimization of HS-SPME GC-MS Method Using a Central Composite Design

The volatile compounds of jambolan (Syzygium cumini L.) fruit were determined at three different maturity stages (unripe, half-ripe, and ripe) by headspace solid-phase microextraction (HS-SPME)–gas chromatography-mass spectrometry (GC-MS) technique using five different fibers (Fused silica PDMS/DVB, DVB/CAR/PDMS, PEG, Stable flex PDMS/DVB, and PDMS). The optimal extraction conditions were evaluated using different variables such as adsorption temperature (minimum 25 °C, maximum 55 °C), salt quantity (minimum 0, maximum 30.0%), and extraction time (min 10, max 30 min). The major classes of compounds identified were ester, terpene, alcohol, aldehyde, and carboxylic acid. Ninety volatile compounds with characteristics aroma attributes were identified, and the primary compounds linked with development of characteristics aroma of ripe jambolan fruit pulp were trans-β-ocimene, β-ocimene, caryophyllene, humulene, D-α-pinene, L-β-pinene, β-pinene, D-limonene, α-terpineol, neo-allo-ocimene, 2-hexenal (E), δ-cadinene, 3-hexen-1-ol, (Z) β-linalool, terpinolene, eremophilene, valencene, 1-hexanol, longipinene, γ-terpinene, γ-muurolene, endo-borneol, o-cymene, nonanal, terpinen-4-ol, β-terpineol, α-muurolene, fenchol, α-fenchene, β-thujene, benzaldehyde, (E)-2-hexenal, β-cadinene, and decanal.     

Gas Chromatography-Mass Spectrometry Analyses for Detection and Identification of Antioxidant Constituents of Achillea tenuifolia Essential Oil

The present work was designed to study the antioxidant activity and to identify the main active components of the essential oil of Achillea tenuifolia aerial parts. Gas chromatography-mass spectrometry analyses of the essential oil showed the presence of 22 compounds. The main constituents of the oil were thymol (15%), α-pinene (10.11%), Camphene (9.41%), β-pinene (7.54%), α-terpinene (7.21%), p-cymene (4%), 1,8-cineole (2.31%), γ-terpinene (7%), linalool (10%), and carvacrol (20.43%). The antioxidant and free radical scavenging activities of Achillea tenuifolia oil was evaluated by using 2,20-diphenyl-1-picrylhydrazyl assays. The oil exhibited a considerable dose-dependent antioxidant activity. Thymol showed clearly a higher activity (IC50 = 10.04 ± 0.1 μg/ml) followed by Achillea tenuifolia essential oil (15.12 ± 0.4 μg/ml). Antioxidant activity guided fractionation of the oil was carried out by the thin layer chromatography-bioautography screening and fractionation resulted in the separation of the main antioxidant compound which was identified as thymol (80%).     

Characterization of volatile compounds in ten Piper species cultivated in Hainan Island,South China

The volatile compounds of 10 Piper species cultivated in Hainan Island, China, have been investigated. Eighty compounds were profiled after headspace–solid phase microextraction (HS–SPME) with gas chromatography–mass spectrometry (GC–MS). Mean Bray–Curtis similarity value was only 22.78 ± 1.98% among the different Piper species. The volatile compounds were largely grouped as hydrocarbons, aldehydes, alcohols, acids, ketones, esters, and phenols. The main compounds comprised benzaldehyde, cinnamaldehyde, β-caryophyllene, ocimene, lavandulol, myrcene, cubebene, terpinene, linalool, α-caryophyllene, β-elemene, and germacrene. Principal component analysis revealed that Piper laetispicum, Piper longum, Piper hainanense, Piper betle, and Piper flaviflorum were characterized by high contents of β-caryophyllene, α-caryophyllene, germacrene, and β-pinene. Piper puberulum and Piper cathayanum were associated with high contents of linalool, myrcene, and germacrene D. On the other hand, Piper pseudofuligineum and Piper retrofractum were related with high contents of ocimene. Finally, Piper auritum was associated with high content of cinnamaldehyde. Volatile profiling of Piper species by HS–SPME–GC–MS and the interrelationship investigated among the volatiles can be used as a roadmap for future resource utilization or biotechnological applications.     

Chemical Composition and Antioxidant Activity of Essential Oil and Methanolic Extracts of Ferula microcolea (Boiss.) Boiss (Apiaceae)

The essential oils of Ferula microcolea, collected from west Iran were obtained by hydrodistillation during the flowering stage and analyzed by gas chromatography and gas chromatography/mass spectrometry. Under the optimum conditions of analysis, 22 constituents (mainly monoterpen compounds) were identified in Ferula microcolea, representing 93.6% of the oil. The main constituents were α-pinene (27.3%), β-pinene (16.4%), nonanal (8.7%), β-caryophyllene (8.5%), and thymol (6.7%). The samples were also subjected to screening for their possible antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl and β-carotene-linoleic acid assays. In the first case, the free radical-scavenging activity of polar sub-fraction of methanol extract showed to be superior as compared to other extracts (IC₅₀ = 34.3 ± 0.3 μg/ml). Nonpolar sub-fraction of methanol extract exhibited stronger activity than the essential oil. In the case of the linoleic acid system, oxidation of the linoleic acid was effectively inhibited by the polar sub-fraction of methanol extract (86.5 ± 0.9%), while the oil and nonpolar sub-fraction of methanol extract were less effective (55.2 ± 0.4% and 81.5 ± 0.8%, respectively).     

Characterization of Aroma Active Compounds of Cumin (Cuminum cyminum L.) by GC-MS,E-Nose,and Sensory Techniques

Profiling of cumin (Cuminum cyminum L.) essential oils, from eight samples (S1–S8) grown in different regions of India, was carried out by gas chromatography-mass spectroscopy, gas chromotography-olfactometry, sensory profiling, and electronic nose techniques. GC-MS analysis showed that the major compounds present in cumin were cuminal (8–17%), β-pinene (22–27%), β-myrcene (1.3–1.75%), ρ-cymene (23–39%), γ-terpinene (11–27%), and ρ-mentha-1,4-dien-7-ol (1.0–5.5%). γ-Terpinene content was 26.36 and 27.73% in S7 and S8 samples, which were collected from the northern region of India, respectively. Sensory odour profiling indicated that samples S7 and S8 had significantly (p ≤ 0.05) higher intensity of floral, cumin-like, and citrussy aroma notes. Principal component analysis revealed that samples S7 and S8 were associated more with floral, citrussy, and cumin-like aroma notes. An electronic nose was found useful to differentiate odour pattern. This study revealed the differences in odour profile of cumin samples of different regions. Thus, these results are useful in the development of designer flavours foods containing spice essential oil.     

Identification of the Volatile Constituents of the Egyptian Lemongrass Oil. Part I. Gas Chromatographic Analysis

The analysis of the Egyptian Lemongrass oil by gas chromatography indicated that about 28 compounds were clearly detected from which 17 only were known. The intensities of the identified components proved that Citral is the main constituent in the Egyptian Lemongrass and showed 78% intensity. The identified alcohols namely linalool, geraniol and citronellol have intensities of 7.25, 33 and 35% respectively. The major hydrocarbons of the Egyptian Lemongrass oil are d-cadenine, d-limonene, α-pinene and α-caryophylline. Their intensities were 42.75, 22.25, 13.50 and 15% respectively. The other hydrocarbons showed lower concentrations.     

High resolution gas chromatographic-mass spectrometric determination of the flavour composition of marjoram (Origanum majorana L.) cultivated in Finland

Capillary gas chromatography and mass spectrometry were used to analyse the composition of the essential oils of marjoram (Origanum majorana L.) cultivated in Finland. A total of 56 compounds were identified, of which 18 are now reported for the first time as constituents of marjoram oil. The compounds identified included 18 hydrocarbons, 17 alcohols, 10 carbonyl compounds, seven esters, two ethers, one phenol and one acid. The most prominent components werecis-sabinene hydrate (8–43 % of the oil) and 4-terpineol (21–52% of the oil), and together withtrans-sabinene hydrate, α-terpineol and linalool they comprized from 71 to 84% of the essential oil. The amount of volatiles was about 50% higher in the plants cultivated under cover than in the plants grown out-doors.     

Chemical composition of the essential oil of marjoram (Origanum majorana L.) from Reunion Island

Capillary gas chromatography, mass and FTIR spectrometry were used to analyse the composition of the water-distilled essential oil of marjoram (Origanum majorana L.) grown in Reunion Island located in Indian Ocean (21°S 55°E). Among 45 compounds recorded by gas chromatography, GC–MS and GC–FTIR 43 components were identified. The essential oil was found to be rich in terpinen-4-ol (38.4%), cis-sabinene hydrate (15.0%), p-cymene (7.0%) and γ-terpinene (6.9%). ©     

Analysis of the aroma compounds of the fruit extracts of Spondias cytherea ("ambarella") from Cameroon

The aroma compounds of extracts of ripe and unripe fruits of Spondias cytherea Sonnerat ("ambarella" or "cajarana") were analysed by GC/FID, GC/MS and olfactometry. As main compounds, 1,8-cineole, α-pinene, β-pinene, terpinolene, limonene, α-terpineol, butyl acetate, γ-terpinene and terpinen-4-ol, among more than 50 constituents, were identified. The characteristic odour impressions of these extracts can be correlated to identified minor alcohols and esters, monoterpenes, hexane derivatives and fatty acids.