Characterization of the odor-active volatiles in citrus Hyuganatsu (Citrus tamurana Hort. ex Tanaka)

The volatile components of Hyuganatsu (Citrus tamurana Hort. ex Tanaka) peel oil, isolated by cold-pressing, were investigated by chemical and sensory analyses. According to chemical analysis by GC and GC-MS, limonene (84.0%) was the most abundant compound, followed by gamma-terpinene (6.9%), myrcene (2.2%), alpha-pinene (1.2%), and linalool (1.0%). Monoterpene hydrocarbons were predominant in Hyuganatsu peel oil. The odor-active volatiles in Hyuganatsu flavor were studied by GC-olfactometry and omission tests. The characteristic flavor was present in the oxygenated fraction. Flavor dilution (FD) factors of the volatile flavor components of the Hyuganatsu cold-pressed oil were determined by aroma extraction dilution analysis (AEDA). Furthermore, relative flavor activity was investigated by means of FD factor and weight percent. Ten kinds of odor compounds having Hyuganatsu-like aroma were detected by AEDA: limonene, linalool, octanol, neral, neryl acetate, tridecanal, trans-carveol, cis-nerolidol, trans,trans-farnesyl acetate, and trans,trans-farnesol. Linalool and octanol were regarded as the most odor-active or key compounds of Hyuganatsu aroma. Diluted solutions of linalool and octanol of approximately 2 ppm gave a fresh and fruity aroma note similar to Hyuganatsu flavor.     

Volatile components of peel and leaf oils of lemon and lime species

Peel and leaf oils of 43 taxa of lemons and limes were obtained from fruits and leaves collected from trees submitted to the same pedoclimatic and cultural conditions. Their chemical composition was investigated by capillary GC, GC-MS, and (13)C NMR, and the results were submitted to principal component analysis to check for chemical variability. Three major chemotypes were distinguished for lemon peel oils: limonene; limonene/beta-pinene/gamma-terpinene; and limonene/linalyl acetate/linalool. Two chemotypes were identified for lemon leaf oils: limonene/beta-pinene/geranial/neral and linalool/linalyl acetate/alpha-terpineol. In lime peel oils, four chemotypes were distinguished: limonene; limonene/gamma-terpinene; limonene/beta-pinene/gamma-terpinene; and limonene/gamma-terpinene/beta-pinene/oxygenated products. Four others were identified for lime leaf oils: beta-pinene/limonene; limonene/geranial/neral; limonene/linalool/citronellal; and limonene/sabinene/citronellal/linalool. These results were interpreted using principal component analysis.     

Differences in the volatile components and their odor characteristics of green and ripe fruits and dried pericarp of Japanese pepper (Xanthoxylum piperitum DC.)

The essential oils of green and ripe fruits and dried pericarp of Japanese pepper (Xanthoxylum piperitum DC.), which are commonly used in Japanese dishes as spices, were extracted with methanol, followed by adsorption to Porapak Q resin. Their aroma profiles were characterized by a sensory evaluation, and their chemical constituents were investigated by using gas chromatography (GC), gas chromatography-mass spectrometry, and aroma extract dilution analysis. Geraniol, citronellal, linalool, and methyl cinnamate were perceived to be important to the basic flavor of the three samples of Japanese pepper by GC-sniffing at high flavor dilution (FD) factors. Monoterpene hydrocarbons constituting almost 76% of the essential oil are the major flavor compounds in the green fruit, and the stronger green and pine leaf notes in the green fruit were considered to be imparted mainly by the large amount of d-limonene, beta-phellandrene, and myrcene due to their high FD factors. On the other hand, the oxygenated terpenes including citronellal, geraniol, and geranial are predominant for the potent odorant in the ripe fruit. The marked citrus-like note in the ripe fruit was thought to be due to the amounts of geranial and citronellal, being 20% of the essential oil. In the dried pericarp, the ratio of oxygenated terpenoids was almost equal to that of monoterpene hydrocarbons. These seemed to induce the flavor character of the dried pericarp to be milder than that of the ripe fruit.     

Composition and antifungal activity on soil-borne pathogens of the essential oil of Salvia sclarea from Greece

The hydrodistilled essential oils of the aerial parts of wild-growing Salvia sclarea originated from two localities in Greece were analyzed by GC-MS. Sixty-six compounds, representing 93.26-98.19% of the oils, were identified. Linalyl acetate (19.75-31.05%), linalool (18.46-30.43%), geranyl acetate (4.45-12.1%), and alpha-terpineol (5.08-7.56%) were the main components. The antifungal activity of the oil of one locality and of the main components, linalyl acetate and linalool, was evaluated in vitro against three soil-borne pathogens.     

Chemical composition of the essential oils of Juniperus from ripe and unripe berries and leaves and their antimicrobial activity

The composition of the essential oil from ripe and unripe berries and leaves of Juniperus oxycedrus L. ssp. oxycedrus, Juniperus phoenicea ssp. turbinata and Juniperus communis ssp. communis was analyzed by GC-MS, and microbiological assays were carried out. Samples were collected in different localities (Sardinia, Italy) and hydro distilled. The yields ranged between 2.54% +/- 0.21 (v\w dried weight) and 0.04% +/- 0.00. A total of 36 components were identified. The major compounds in the essential oils were alpha-pinene, beta-pinene, delta-3-carene, sabinene, myrcene, beta-phellandrene, limonene, and D-germacrene. Both qualitative and quantitative differences between species and between different parts of the plant were observed. The essential oils and their major compounds were tested against Candida albicans, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, and the minimum inhibitory concentration and minimum bactericidal concentration were determined. The results obtained led to a nonsignificant inhibitory effect, although all the essential oils from Juniperus phoenicea ssp. turbinata and the essential oil from leaves of Juniperus oxycedrus ssp. oxycedrus exhibited rather good or weak activity against Candida albicans and Staphylococcus aureus.     

Uruguayan essential oil. 12. Composition of Nova and Satsuma mandarin oils

The composition of the laboratory-prepared essential oils from Uruguayan Nova and Satsuma mandarins has been studied. The volatile fraction was analyzed by HRGC and HRGC/MS (quadrupole); 79 and 73 components were identified in Nova and Satsuma mandarin oils, respectively. The linear retention indices were calculated for almost all identified components on two different stationary phases. The enantiomeric distribution of beta-pinene, sabinene, limonene, linalool, and alpha-terpineol was studied by multidimensional gaschromatography (MDGC). Polymethoxylated flavones, present in the nonvolatile residue, were analyzed by normal-phase HPLC.     

Chemical composition of volatiles in Sardinian myrtle (Myrtus communis L.) alcoholic extracts and essential oils

The chemical composition of the volatile fraction of myrtle (Myrtus communis L.) alcoholic extracts and essential oils from leaves and berries collected in different places in Sardinia (Italy) was studied. A simple and rapid liquid-liquid extraction method was used to isolate volatile compounds from myrtle alcoholic extracts followed by GC and GC-MS analysis allowing the detection of 24 compounds. The volatile fraction was characterized by the terpenes fraction corresponding to that of the essential oils and by a fatty acid ethyl esters fraction. The variation during extraction of the volatile fraction in alcoholic extracts of berries and leaves was evaluated. Essential oils were obtained by hydrodistillation, and the yields were on average 0.52 +/- 0.03% (v/w dried weight) and 0.02 +/- 0.00% for leaves and berries, respectively. The essential oils were analyzed by GC and GC-MS, and a total of 27 components were detected, accounting for 90.6-98.7% of the total essential oil composition. Strong chemical variability depending on the origin of the samples was observed. The major compounds in the essential oils were alpha-pinene (30.0 and 28.5%), 1,8-cineole (28.8 and 15.3%), and limonene (17.5 and 24.1%) in leaves and berries, respectively, and were characterized by the lack of myrtenyl acetate.     

Screening of chemical composition and antifungal and antioxidant activities of the essential oils from three Turkish artemisia species

The compositions of essential oils isolated from the aerial parts of Artemisia absinthium, Artemisia santonicum, and Artemisia spicigera by hydrodistillation were analyzed by GC-MS, and a total of 204 components were identified. The major components of these essential oils were camphor (34.9-1.4%), 1,8-cineole (9.5-1.5%), chamazulene (17.8-nd%), nuciferol propionate (5.1-nd%), nuciferol butanoate (8.2-nd%), caryophyllene oxide (4.3-1.7%), borneol (5.1-0.6%), alpha-terpineol (4.1-1.6%), spathulenol (3.7-1.3%), cubenol (4.2-0.1%), beta-eudesmol (7.2-0.6%), and terpinen-4-ol (3.5-1.2%). The antifungal activities of these essential oils were tested against 11 plant fungi and were compared with that of a commercial antifungal reagent, benomyl. The results showed that all of the oils have potent inhibitory effects at very broad spectrum against all of the tested fungi. Pure camphor and 1,8-cineole, which are the major components of the oils, were also tested for antifungal activity against the same fungal species. Unlike essential oils, these pure compounds were able to show antifungal activity against only some of the fungal species. In addition, the antioxidant and DPPH radical scavenging activities of the essential oils, camphor, and 1,8-cineole were determined in vitro. All of the studied essential oils showed antioxidant activity, but camphor and 1,8-cineole did not.     

Repellent activity of essential oils and some of their individual constituents against Tribolium castaneum herbst

A tool for integrated pest management is the use of essential oils (EOs) and plant extracts. In this study, EOs from Tagetes lucida , Lepechinia betonicifolia , Lippia alba , Cananga odorata , and Rosmarinus officinalis , species grown in Colombia, were analyzed by gas chromatography-mass spectrometry. These oils as well as several of their constituents were tested for repellent activity against Tribolium castaneum , using the area preference method. The main components (>10%) found in EOs were methylchavicol, limonene/α-pinene, carvone/limonene, benzyl acetate/linalool/benzyl benzoate, and α-pinene, for T. lucida, L. betonicifolia, L. alba, C. odorata, and R. officinalis, respectively. All EOs were repellent, followed a dose-response relationship, and had bioactivity similar to or better than that of commercial compound IR3535. EOs from C. odorata and L. alba were the most active. Compounds from EOs, such benzyl benzoate, β-myrcene, and carvone, showed good repellent properties. In short, EOs from plants cultivated in Colombia are sources of repellents against T. castaneum.     

Determination of the chemical composition and antioxidant activity of the essential oil of Artemisia dracunculus and of the antifungal and antibacterial activities of Turkish Artemisia absinthium, A. dracunculus, Artemisia santonicum, and Artemisia spicigera essential oils

The essential oil isolated from Turkish tarragon (Artemisia dracunculus) by hydrodistillation was analyzed by GC-MS. Thirty compounds representing 99.5% of total oil were identified. The predominant components in the oil were (Z)-anethole (81.0%), (Z)-beta-ocimene (6.5%), (E)-beta-ocimene (3.1%), limonene (3.1%), and methyleugenol (1.8%). The antibacterial and antifungal activities of the essential oils isolated from A. dracunculus, Artemisia absinthium, Artemisia santonicum, and Artemisia spicigera oils were also evaluated. In general, the oils exhibited potent antifungal activity at a wide spectrum on the growth of agricultural pathogenic fungi. Among the oils, the weakest antifungal activity was shown by the oil of A. dracunculus. In many cases, the oils of A. absinthium, A. santonicum, and A. spicigera completely inhibited the growth of some fungal species. As compared with antibacterial activities of all of tested oils, A. santonicum and A. spicigera oils showed antibacterial activities over a very wide spectrum. However, the essential oils tested showed lower inhibition zones than the inhibition zones of penicillin. In addition, antioxidant and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of tarragon oil were determined, and weak antioxidant and DPPH radical scavenging activities were found in comparison to butylated hydroxytoluene.     

Variation of major volatile constituents in various green teas from Southeast Asia

A total of 15 green tea samples were prepared from fresh tea leaves obtained from three different countries: two from Laos, seven from Myanmar, and six from Vietnam. The volatile aroma constituents of the 15 samples were analyzed by gas chromatography/mass spectroscopy. Eleven aroma constituents were chosen from over 100 chemicals found in the samples to compare differences among various teas. They were hexanal, 1-penten-3-ol, heptanal, 1-pentenal, (Z)-2-penten-1-ol, (Z)-3-penten-1-ol, linalool oxide (trans-furanoid), linalool oxide (cis-furanoid), linalool, linalyl propanoate, and geraniol. Generally, concentrations of linalool and hexanal seem to play an important role in the quality of green teas. Green teas from Laos and Myanmar contained heterocyclic compounds, such as pyridines and pyrazines, formed by high-temperature processing. The presence of these heterocyclic compounds suggested that the temperature used for tea processing plays an important role in the formation of aroma chemicals in green teas.     

Repellent constituents of essential oil of Cymbopogon distans aerial parts against two stored-product insects

The screening for bioactive principles from several Chinese medicinal herbs showed that the essential oil of Cymbopogon distans aerial parts possessed strong repellency against the booklouse, Liposcelis bostrychophila , and the red flour beetle, Tribolium castaneum . A total of 36 components of the essential oil were identified by GC and GC-MS. trans-Geraniol (16.54%), (R)-citronellal (15.44%), (+)-citronellol (11.51%), and α-elemol (9.06%) were the main components of the essential oil followed by β-eudesmol (5.71%) and (+)-limonene (5.05%). From the essential oil, four monoterpenes were isolated by bioassay-guided fractionation. The compounds were identified as limonene, citronellol, citronellal, and trans-geraniol. Geraniol and citronellol were strongly repellent against the booklouse, L. bostrychophila, whereas citronellal and limonene exhibited weak repellency against the booklouse. Geraniol and citronellol exhibited comparable repellency against the booklouse relative to the positive control, DEET. Moreover, geraniol and citronellol exhibited stronger repellency against the red flour beetle than DEET, whereas the two other compounds showed the same level of repellency against the red flour beetle compared with DEET.     

Composition and antimicrobial activity of the essential oils of two Origanum species

The essential oils obtained from the aerial parts of Origanum scabrum and Origaum microphyllum, both endemic species in Greece, were analyzed by means of GC and GC-MS. Forty-eight constituents were identified, representing 98.59 and 98.66% of the oils, respectively. Carvacrol, terpinen-4-ol, linalool, sabinene, alpha-terpinene, and gamma-terpinene were found as the major components. Furthermore, both samples exhibited a very interesting antimicrobial profile after they were tested against six Gram-negative and -positive bacteria and three pathogenic fungi.     

Characterization of essential oils from lamiaceae species by fourier transform Raman spectroscopy

The Fourier transform Raman (FT-Raman) spectra of pure terpenes and essential oils obtained by hydrodistillation of some Lamiaceae species, are presented. This study shows that principal components of an essential oil can be recognized by FT-Raman. Components predicted by FT-Raman spectrum of an essential oil correlate well with those found as major constituents by GC-MS. In this way the basic chemical character of an essential oil can be recognized. The results demonstrate that certain Raman intensities can be correlated to specific terpenes and therefore FT-Raman can discriminate between the essential oils of which main components belong to different classes of compounds.     

Essential oils produced by in vitro shoots of sage (Salvia officinalis L.)

In vitro shoots of sage (Salvia officinalis L.) were established under eight different hormonal supplementations and proliferated by subculture of nodal shoot segments. The respective essential oils, obtained by hydrodistillation, were composed of more than 75 compounds, 65 of which were identified. The 10 major compounds were, by order of retention time, alpha-pinene (4.1-5.4%), camphene (6-7.1%), beta-pinene (9.3-14.5%), limonene (2-2.3%), 1,8-cineole (3.6-5.6%), (-)-thujone (13.2-16.1%), (+)-isothujone (6.6-7.4%), camphor (19.8-24%), alpha-humulene (5.1-6.8%), and manool (4.2-7.7%). Notwithstanding the eight different hormonal supplementations tested, the percentage composition of the shoot essential oils were kept in a narrow range of variation. However, the type and concentration of growth regulators apparently influenced the accumulation of essential oils. The highest accumulation of essential oils and the highest shoot biomass growth were obtained with 2.0 mg/L kinetin and 0.05 mg/L 2,4-dichlorophenoxyacetic acid.     

Screening for key odorants in Moroccan green olives by gas chromatography-olfactometry/aroma extract dilution analysis

"Spanish style" Moroccan green table olives were screened for potent odorants by gas chromatography-olfactometry/aroma extraction dilution analysis of a representative Likens-Nickerson extract. (Z)-3-Hexenal [flavor dilution factor (FD) = 256], (E,E)-2,4-decadienal (FD = 128), and (E,Z)-2,4-decadienal (FD = 64) were revealed to confer green and coriander/paraffin oil odors to both fruit and oil extracts, whereas guaiacol (FD = 128) imparted a bad olive, phenolic note. Methional (3-methylthiopropionaldehyde, FD = 128) and several terpenes (FD 相似文献   

Linalool from Lippia alba: study of the reproducibility of the essential oil profile and the enantiomeric purity

A new chemotype of the aromatic Verbenaceae species Lippia alba Mill. N. E. Br. from southeastern Brazil has recently been shown to have a high content of linalool in the leaf essential oil. Vegetative propagation of this chemotype was conducted at six different locations in Brazil, and the variation of the content and the optical purity of linalool in the oils were verified. Yields (0.6-0.9%, hydrodistillation), chemical composition, linalool content, and optical purity of the oils from all the plants were compared, using GC-FID, GC-MS, chiral chromatography, and retention index calculation. No plant exceeded the matrix in linalool content (46.5 to 90.7%), and the chemical profile of the oils was the same for all the samples. Purification of linalool to a content close to 100% was effected by vacuum distillation of the crude oil. Chiral analysis showed exclusively the presence of S-linalool in all the crude oils and in the distilled samples.     

Volatile constituents and key odorants in leaves, buds, flowers, and fruits of Laurus nobilis L

The volatiles of fresh leaves, buds, flowers, and fruits from bay (Laurus nolilis L.) were isolated by solvent extraction and analyzed by capillary gas chromatography-mass spectrometry. Their odor quality was characterized by gas chomatography-olfactometry-mass spectrometry (HRGC-O-MS) and aroma extract dilution analysis (AEDA). In fresh bay leaves 1,8-cineole was the major component, together with alpha-terpinyl acetate, sabinene, alpha-pinene, beta-pinene, beta-elemene, alpha-terpineol, linalool, and eugenol. Besides 1,8-cineole and the pinenes, the main components in flowers were alpha-eudesmol, beta-elemene, and beta-caryophyllene, in fruits (E)-beta-ocimene and biclyclogermacrene, and in buds (E)-beta-ocimene and germacrene D. The aliphatic ocimenes and farnesenes were absent in leaves. By using HRGC-O-MS 21 odor compounds were identified in fresh leaves. Application of AEDA revealed (Z)-3-hexenal (fresh green), 1,8-cineole (eucalyptus), linalool (flowery), eugenol (clove), (E)-isoeugenol (flowery), and an unidentified compound (black pepper) with the highest flavor dilution factors. Differences between buds, flowers, fruits, and leaves with regard to the identified odor compounds are presented.     

Character impact odorants of Citrus Hallabong [(C. unshiu Marcov x C. sinensis Osbeck) x C. reticulata Blanco] cold-pressed peel oil

The volatile components of Hallabong ([C. unshiu Marcov x C. sinensis Osbeck] x C. reticulata Blanco) cold-pressed peel oil were quantitatively and qualitatively determined by use of two internal standards with GC, GC-MS, and GC-olfactometry. According to instrumental analysis by GC and GC-MS, limonene (90.68%) was the most abundant compound, followed by sabinene (2.15%), myrcene (1.86%), and gamma-terpinene (0.88%). Flavor dilution (FD) factors of the volatile flavor components from Hallabong peel oil were determined by aroma extract dilution analysis. Furthermore, relative flavor activity was investigated by means of FD factor and weight percent. The highest FD factors were found for citronellal and citronellyl acetate, and delta-murollene showed a higher relative flavor activity. Results of sniff testing of the original oil and its oxygenated fraction revealed that citronellal, cis-beta-farnesene, and citronellyl acetate were regarded as the character impact odorants of Hallabong peel oil, and citronellal gave the most odor-active character of Hallabong aroma.     

Comparison of the essential oils of Glehnia littoralis from Northern and Southern Japan.

The essential oils from aerial and root parts of Glehnia littoralis were investigated by GC and GC-MS, and 125 compounds were identified. Plants were obtained from Northern and Southern Japan, and samples from the same locations were cultivated either exposed or unexposed to sunlight. The main constituents of the essential oils were found to be alpha-pinene (0.03-13.40%), limonene (0.15-10.71%), beta-phellandrene (0.03-22.93%), germacrene B (0.27-8.33%), spathulenol (0.24-6.50%), beta-oplopenone (0.06-6.47%), panaxynol (0.38-24.58%), propyl octanoate (3.44-27.85%), hexadecanoic acid (0.45-27.80%), and linoleic acid (0.16-17.56%). Terpenoid compounds were found in higher concentrations in the Northern type oils than in the Southern types, whereas the concentration of polyacetylenic compounds was higher in one of the Southern samples, except from the aerial parts of those cultivated exposed. Consequently, the constitution of the essential oils from G. littoralis could be separated into Northern and Southern types.