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PubMedDate not supplied

A basis for estimation of consumption: literature values for selected food volatiles. Part III.

Quantitative data on volatile compounds have been reported in 16 food items. No publications reporting quantitative data were found for two of these 16 food products, i.e. avocado and jackfruit. About 550 volatile compounds have been assayed globally in the other 14 food products. Mango and raspberry were the products with the greatest number of volatile compounds; the most representative substances were benzaldehyde, ethyl acetate, limonene, and 2-phenylethanol.

Flavoring Agents↗
PubMed2003

Biosynthesis and emission of terpenoid volatiles from Arabidopsis flowers.

Arabidopsis is believed to be mostly self-pollinated, although several lines of genetic and morphological evidence indicate that insect-mediated outcrossing occurs with at least a low frequency in wild populations. Here, we show that Arabidopsis flowers emit both monoterpenes and sesquiterpenes, potential olfactory cues for pollinating insects. Of the 32 terpene synthase genes in the Arabidopsis genome, 20 were found to be expressed in flowers, 6 of these exclusively or almost exclusively so. Two terpene synthase genes expressed exclusively in the flowers and one terpene synthase gene expressed almost exclusively in the flowers were characterized and found to encode proteins that catalyze the formation of major floral volatiles. A beta-glucuronidase fusion construct with a promoter of one of these genes demonstrated that gene expression was restricted to the sepals, stigmas, anther filaments, and receptacles, reaching a peak when the stigma was receptive to cross pollen. The observation that Arabidopsis flowers synthesize and emit volatiles raises intriguing questions about the reproductive behavior of Arabidopsis in the wild and allows detailed investigations of floral volatile biosynthesis and its regulation to be performed with this model plant system.

Alkyl and Aryl Transferases↗
PubMed2025

Integrated genomic, transcriptomic, and metabolomic analyses of Chrysanthemum aromaticum provide insights into the volatile terpene biosynthesis.

Chrysanthemum aromaticum is renowned for its uniformly emitted strong and attractive scent, primarily attributed to volatile terpenes. Despite its commercial and horticultural significance, the molecular mechanisms underlying volatile terpene production in C. aromaticum remain largely unexplored. Here, we present the haplotype-resolved genome assembly of C. aromaticum, with a total size of 3.10 Gb, comprising nine anchored chromosomes with a contig N50 of 30.66 Mb and a scaffold N50 of 350.58 Mb. Phylogenetic analyses revealed a distant relationship between C. aromaticum and C. indicum, suggesting that C. aromaticum likely represents a distinct species rather than a variety of C. indicum. Through integrated genomic, transcriptomic, metabolomic, and biochemical analyses, we identified seven TPS involved in monoterpene biosynthesis and six TPS for sesquiterpene biosynthesis. Notably, comparative genomic analysis revealed a gene cluster for α-bisabolol biosynthesis in C. aromaticum, which has specifically expanded in Chrysanthemum species through tandem gene duplications, contributing to the elevated accumulation of α-bisabolol in the leaves of C. aromaticum. Our study provides important insights into the biosynthesis of volatile terpenes, highlighting the genetic basis for C. aromaticum's unique aromatic profile.

Chrysanthemum↗
PubMed2006

[Analysis of volatile constituents from leaves of plants by gas chromatography/mass spectrometry with solid-phase microextraction].

A method for analyzing volatile constituents from plant leaves with gas chromatography/mass spectrometry (GC/MS) coupled with solid-phase microextraction (SPME) was developed. The volatile compounds from the plant leaves inside a sealed flask maintained at 45 degrees C in a water bath were efficiently extracted with Polyacrylate (85 microm) SPME fibers prior to perform GC/MS analysis. The GC/MS analysis indicated that the volatile compounds from the plant leaves which is easy to be damaged by Tetraychus vienneis include relative large amounts of cis-3-hexenyl ester acetic acid, cis-3-hexenyl ester butanoic acid and alpha-famesene. These compounds were preliminarily confirmed to be accountable for attracting Tetraychus vienneis. This finding may lead to identify biological species for preventing and treating Tetraychus vienneis.

Clinical Laboratory Techniques↗
PubMed2004

Application of HS-SPME and GC-MS to characterization of volatile compounds emitted from Osmanthus flowers.

Headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) was developed for characterization of volatile compounds emitted from two varieties Osmanthus flowers of O. fragrans var. latifolius and O. fragrans var. thunbergii. The SPME parameters were studied, the optimum conditions of a 65 microm carbowax/divinylbenzene (CW/DVB), extraction temperature of 22 degrees C and extraction time of 10 min were obtained and applied to extraction of the volatile emissions. Fourteen compounds released from both varieties of Osmanthus flowers were separated and identified by GC-MS, which mainly included alpha-linalool, beta-linalool, trans-linalool oxide, cis-linalool oxide, alpha-lonone, beta-lonone, capraldehyde and decalactone. By comparing their peak areas, we found that the sums of the fourteen compounds from the two Osmanthus flowers were very close, while the relative contents of individual volatile compounds in the two emissions were very different. The relative content of alpha-linalool and beta-linalool in O. fragrans var. latifolius were 39.46% and 0.51%, while in O. fragrans var. thunbergii were 9.53% and 27.71%. Due to their different relative contents, the two varieties of flower have different fragrances.

Aldehydes↗
PubMed2006

Identification of volatile components in Angelica species using supercritical-CO2 fluid extraction and solid phase microextraction coupled to gas chromatography-mass spectrometry.

As a part of our search for environmentally friendly solvents to extract the active components of medicinal plants, two sampling techniques, supercritical fluid extraction (SFE) using CO(2) and solid-phase microextraction (SPME) were compared for their efficacy in the analysis of volatiles rhizome components emitted from the medicinal herbs Angelica gigas NAKAI (Korean danggui), Angelica sinensis (Chinese danggui), and Angelica acutiloba (Japanese danggui). A total of 54 compounds released from all of these varieties of Angelica rhizomes were separated and identified by gas chromatography-mass spectrometry (GC-MS). The composition of supercritical extracts from these plants was very different from the solid-phase microextraction products. More compounds were detected by SPME-GC-MS (41) than by SFE-GC-MS (17). The results of these analyses suggest that SFE may be useful for detecting the main components, decursinol angelate and decursin in Korean danggui, and butylidene dihydro-phthalide in both Chinese and Japanese danggui, whereas the results for SPME did not. The SFE method required specialized instrumentation, required little time to prepare the sample, and had a small sample size and no organic solvent. In sum, these results suggest that SFE is useful for extracting the volatile main components of danggui cultivars. Its simplicity, low cost and speed may allow SPME to increase the recovery of volatile components in general without disturbing the main components of the plant.

Angelica↗
PubMed2005

Volatile organic compounds from arctic bacteria of the Cytophaga-Flavobacterium-Bacteroides group: a retrobiosynthetic approach in chemotaxonomic investigations.

Volatile organic compounds emitted by different marine arctic strains of the Cytophaga-Flavobacterium-Bacteroides group were investigated by using a modified closed-loop stripping apparatus (CLSA). Seven of nine strains emitted volatiles, dominated by methyl ketones, in specific patterns. The methyl ketones were aliphatic saturated, or unsaturated, and comprised 12 to 18 C-atoms, sometimes with terminal Me branches. They were identified by GC/MS, retention-index calculations, derivatization with dimethyl disulfide for C=C bond location, and GC/FTIR to elucidate their uniform (Z)-configuration. The proposed structures of all methyl ketones were subsequently confirmed by synthesis, while the absolute configuration of chiral volatiles was elucidated by stereoselective synthesis. From retrobiosynthetic considerations, it was found that strain ARK10267 uses mainly valine, and strain ARK10063 mainly isoleucine for formation of starters for the ketone biosynthesis, which is correlated to fatty acid biosynthesis. Four strains (ARK10223, ARK10044, ARK10141, and ARK10146) use leucine. These separations are supported by phylogenetic affiliations based on 16S rRNA. Strain ARK10255b, in the course of this study found to be not a member of the Cytophaga-Flavobacterium-Bacteroides phylum, did not emit aliphatic ketones of medium chain length, but methionine-derived 4-(methylsulfanyl)butan-2-one and corresponding 4-(methylsulfanyl)butan-2-ol. Most of the compounds described have not been reported previously from nature.

Arctic Regions↗
PubMed2005

Volatiles released by a Streptomyces species isolated from the North Sea.

The North Sea Streptomyces strain GWS-BW-H5 was investigated by analyzing headspace extracts of agar-plate cultures (HE) or liquid cultures (LCE), obtained with a closed-loop stripping apparatus (CLSA), by GC/MS (Table 1). The volatile profile of the HE is dominated by the known volatiles (-)-geosmin (4) and 2-methyisoborneol (1). Small amounts of sesquiterpenes occur, which are present in a more-diverse structural variety and in higher quantities in the LCE. The different structures can be rationalized by few cationic intermediates along their biosynthetic pathway. The most-prominent difference between the two culture methods were the presence of the Me-branched gamma- and delta-lactones 31-38, not previously reported from nature, in the LCE. Major components were 10-methyldodecan-5-olide (34), 10-methyldodec-2-en-4-olide (36), and 10-methyldodec-3-en-4-olide (38). The structures of all new lactones were verified by synthesis. Furthermore, more volatiles in higher amounts were produced by the liquid culture than by to the agar plate culture. Since 36 showed inhibitory growth effects against strain GWS-BW-H5, growth inhibition against twelve other strains isolated from the same habitat was tested. Antagonistic activity against four of the strains was observed, with a slightly higher threshold level than found for penicillin G, which was used in control experiments (Table 2).

Molecular Structure↗
PubMed2005

Cytotoxic activity and constituents of the volatile oil from the roots of Patrinia scabra Bunge.

The volatile oil from the roots of Patrinia scabra Bunge was isolated by steam distillation, and separated into four major fractions (Fr. A-D) by means of column chromatography. A total of 39 compounds (1-39) were identified by GC/MS analysis, and evaluated for their in vitro cytotoxic activities against human ovarian carcinoma cells (HO-8910) and human hepatoma cells (Bel-7402) (Table 1). Fr. A showed the strongest inhibitory effect on HO-8910 (IC50 = 21 microg/ml) and Bel-7402 cells (16 mcirog/ml), whereas Fr. B was the least active (>100 microg/ml). By comparison of the constituents of the four fractions, we assume that the cytotoxicity of the volatile oil of P. scabra is mainly due to the lignans and azulenes, rather than to caryophyllene oxide I (18). Our results suggest that the volatile oil of P. scabra possesses potent and tumor-specific cytotoxicity, and could serve as a possible candidate for future cancer chemotherapy.

Antineoplastic Agents, Phytogenic↗
PubMedDate not supplied

Toxicity, immunosuppressive effects and carcinogenic potential of volatile nitrites: possible relationship to Kaposi's sarcoma.

Volatile nitrite in the form of amyl nitrite was used for 100 years for the treatment of angina pectoris. In spite of recognized toxicity, its use in this form was considered safe. During the 1960s prescriptions were not required for purchase of amyl nitrite (called poppers) and its use for recreational purposes became popular. With reinstatement of the prescription requirement in 1969, non-medicinal, street-variety volatile nitrites were made commercially available in the form of mixtures of impure butyl and isobutyl nitrite; some of these preparations also included amyl nitrite. These products have been found to be profoundly immunosuppressive for human lymphocytes in vitro, and their by-products when metabolized into N-nitroso compounds have been known to be highly carcinogenic in many animal species. Recreational use of inhaled volatile nitrites is prevalent among male homosexuals and the compounds have been suspected as possible cofactors in Kaposi's sarcoma associated with the Acquired Immune Deficiency Syndrome (AIDS). This association could be explained by nitrite-induced vasodilation of rectal mucosal vessels providing a port of entry for a transmissible agent, by direct immunosuppression of the host allowing expression of a potentially oncogenic virus by co-carcinogenic effects of by-products by themselves or in conjunction with other putative cofactors such as cytomegalovirus. Nitrites should continue to be considered as a possible cofactor in the etiology of Kaposi's Sarcoma among male homosexuals and possibly those with other manifestations of AIDS.

Amyl Nitrite↗
PubMed2006

Kinetics of finite dose absorption through skin 2: volatile compounds.

A diffusion model to account for the disposition of an arbitrary dose of a (potentially) volatile compound applied to skin from a volatile vehicle is presented. In its most general form, the model allows for variable diffusivity of the permeant in the stratum corneum (SC) and must be solved numerically. However, for permeants having a constant diffusivity, absorption, and evaporation is characterized in terms of four dimensionless parameters-a reduced time tau, a fractional deposition depth in the SC f, a ratio of membrane capacity for the permeant to the applied dose beta, and a ratio of evaporative mass transfer coefficient to diffusive permeability chi. An important combination of these parameters arises as the reduced dose M(r) = (fbeta)(-1). Two cases are distinguished. In Case 1, corresponding to M(r) < or = 1, the dose is less than that required to saturate the upper layers of the SC, and the shape of the absorption and evaporation profiles is independent of the dose. Analytical solutions to Case 1 may be derived for arbitrary initial distributions of the permeant; the solution for a square wave is presented. In Case 2, corresponding to M(r) > 1, absorption and evaporation approach steady-state values as the dose is increased. Numerical evaluations of this behavior are shown. Limiting behavior for the case of a highly volatile solvent applied to skin is discussed. A companion paper discusses the application of the model to the absorption and evaporation of benzyl alcohol from human skin in vitro.

Administration, Cutaneous↗
PubMed2006

Determination of suspected allergens in non-volatile matrices using PTV injection with automated liner exchange and GC-MS.

A method is described for the analysis of suspected volatile allergens in products containing high molecular weight or non-volatile compounds such as plant extracts, solid and liquid detergents, shampoos, etc. The method is based on dissolution/extraction of the sample followed by direct injection in a programmed temperature vaporizing inlet, the liner of which contains PDMS foam to retain the high molecular weight non-volatile material. The liner is automatically replaced after each injection, by an automated liner exchange device. Analysis is done by GC-MS operated in the retention-time locked mode. The figures of merit are illustrated with the analysis of some real samples.

Allergens↗
PubMedDate not supplied

Composition of volatiles of banana cultivars from Madeira Island.

The composition of the volatiles of banana fruit from various cultivars grown on Madeira Island has been determined. Using GC-MS, the volatiles were shown to be complex mixtures of several classes of components, mainly esters, alcohols, aldehydes, ketones and acids. The average contents of the total volatiles from cultivars "Dwarf Cavendish", "Giant Cavendish", "Robusta" and "Williams" were 93.0, 116.5, 157.3 and 157.0 mg/kg, respectively. The ester and alcoholic fractions appear to play a decisive role in the organoleptic characteristics of banana fruit, presenting a substantial content ranging from 57.2 to 89.8 mg/ kg and 19.0 to 47.7 mg/kg, respectively, in all cultivars from Madeira Island studied. 3-Methyl butyl butanoate ester was the major constituent.

Acids↗
PubMed2002

Chemical composition and biological activity of the volatiles of Anthemis melampodina and Pluchea dioscoridis.

The volatile fractions obtained by hydrodistillation of the fresh leaves of Anthemis melampodina and Pluchea dioscoridis were analysed by GC-MS technique. Of 38 components identified in the volatile oil of A. melampodina, santolinatriene was the major component (27.33%). The oil was characterized by a high percentage of monoterpene hydrocarbons (49.94%) while sesquiterpene hydrocarbons and oxygenated sesquiterpenes represented only 7.41% and 11.43% of the oil. 36 components were identified in the volatile oil of P. dioscoridis. Farnesol was the major component (16.50%) accompanied by a high percentage of sesquiterpene alcohols. Oxygenated sesquiterpenes (26.43%) and sesquiterpene hydrocarbons (39.43%) represented the main constituents in the oil. P. dioscoridis showed a marked mosquito larvicidal activity against Culex pipiens (LC(50) 71.86 ppm), while A. melampodina was moderately active (LC(50) 139.42 ppm).

Animals↗
PubMed2005

Identification of volatile basic components in tobacco by headspace liquid-phase microextraction coupled to matrix-assisted laser desorption/ionization with Fourier transform mass spectrometry.

A method incorporating headspace liquid-phase microextraction (HS-LPME) coupled to matrix-assisted laser desorption/ionization (MALDI) with Fourier transform mass spectrometry (FTMS) was established to analyze volatile basic components in tobacco. The sample preparation volume for MALDI-MS was compatible with the volume of the solvent microdrop in the HS-LPME procedure. The pH and the polarity of the solvent for HS-LPME were adjusted by choice of the MALDI matrix and matrix additive. Based on the elemental composition and tandem mass spectrometry information, 25 volatile nitrogenous compounds in tobacco were detected and identified. The approach is fast and sensitive, and has the potential for automation for high-throughput analysis. This approach offers an alternative method for analysis of trace volatile organic compounds in complex samples.

Gas Chromatography-Mass Spectrometry↗
PubMed2005

Major volatile compounds in head-space above olive oil analysed by selected ion flow tube mass spectrometry.

Selected ion flow tube mass spectrometry (SIFT-MS) is a technique that is well suited to the real-time analysis of head-space. SIFT-MS gives a non-discriminatory snapshot of the volatiles present and their amounts, and is considered to display less bias than chromatographic techniques as neither sample pre-treatment nor separation are necessary in most cases. The technique has been used for analysis of virgin olive oil head-space on more than 100 different oils. Twenty of these are reported. The results obtained using this technique differ from those normally reported from chromatographic analyses in that the dominant species in the head-space of all oils tested were methanol and ethanol. These volatiles were present in the head-space in the concentration ranges of 2.8-11.3 ppm (methanol) and 0.4-4.9 ppm (ethanol). (E)-2-Hexenal, normally reported as the dominant olive oil volatile, is found in significantly lower concentrations and is in the range of 0.02-1.6 ppm.

Mass Spectrometry↗
PubMed2001

Choice and use of standards for dynamic headspace trapping and application to the analysis of the volatiles of baked potato.

When attempting to quantify the volatile components of a food isolated by dynamic headspace trapping onto an adsorbent, the analyst has to select the most appropriate compounds to use as standards and at which stage of the analysis to add them. Factors to be borne in mind include the volatility of the standard, the response of the GC detector, and whether to add the standard to the sample or to the adsorbent trap. This chapter considers the issues and describes the application of one chosen method to the quantitation of the volatile components of baked potato.

Calibration↗
PubMed2001

Solvent desorption dynamic headspace sampling of fermented dairy product volatiles.

A method was developed based on solvent desorption dynamic headspace analysis for the identification and relative quantification of volatiles significant to the study of fermented dairy product aroma. Descriptions of applications of this method are presented including the measurement of diacetyl and acetoin in fermented milk, the evaluation of volatile-hydrocolloid interactions in dairy-based matrices, and the identification of volatiles in cheeses for canonical discriminative analysis. Advantages of this method include rapid analysis, minimal equipment investment, and the ability to analyze samples with traditional GC split/splitless inlet systems. Limitations of this method are that the sample must be in the liquid state and the inherent analytical limitation to those compounds that do not coelute with the solvent or solvent impurity peaks.

Adsorption↗