Search results for "Volatile"
showing 10 items of 606 documents
Chemical composition of the essential oil of Salvia microstegia Boiss. et Balansa growing wild in Lebanon.
2005
The essential oil of aerial parts of Salvia microstegia Boiss. et Balansa (Lamiaceae) growing wild in Lebanon was obtained by hydrodistillation and was analysed by GC and GC–MS. 70 compounds, representing 94.0% of the oil, were identified. The major components were caryophyllene oxide (6.2%), pulegone (5.7%), 4-vinylguaiacole (5.3%), hexadecanoic acid (5.1%) and menthone (4.9%). © 2006 Elsevier B.V. All rights reserved.
GC and GC–MS analysis of the essential oil of Nepeta cilicica Boiss. ex Benth. from Lebanon
2013
The hydrodistillation of the aerial parts of Nepeta cilicica Boiss. ex Benth., collected in Lebanon in the Horsh Ehden reserve, yielded 0.13% (w/w) of essential oil. Gas chromatography (GC) and GC-mass spectroscopy analysis enabled the identification of 75 compounds representing 96.8% of the total oil. The most abundant compounds were spathulenol (15.1%), hexadecanoic acid (14%), δ-cadinene (5.5%) and α-copaene (4.5%). On the whole, the oil was constituted mainly by sesquiterpenes (45.9%), among which sesquiterpene hydrocarbons (27.6%) slightly prevailed over oxygenated sesquiterpenes (18.3%).
Volatile components of Centaurea eryngiodes Lam. and Centaurea iberica Trev.var. hermonis Bois. Lam.,two Asteraceae growing wild in Lebanon.
2005
The volatile components of the flowerheads of Centaurea eryngioides Lam. and Centaurea iberica Trev. var. hermonis Boiss. Lam. were obtained by hydrodistillation and identified by GC and GC–MS. Altogether 91 components, mostly fatty acids and hydrocarbons, were identified.
A New Simple Static Method for the Determination of Solubilities of Condensed Compounds in Supercritical Fluids
2002
Abstract A simple static method based on gravimetric measurements has been adopted to measure the solubility of benzenecarboxylic acid, 2-hydroxy-benzenecarboxylic acid, 4-hydroxy-benzenecarboxylic acid and 1,8-dihydroxyanthraquinone along several isotherms in the temperature range 318–357 K and the pressure interval 7–23 MPa. Solubility data have been correlated with the Zieger–Eckert approach, using the Fedor atomic and group contribution method to estimate the solubility parameter and the molar volume of the solutes. A good agreement was obtained between data reported in the literature and those determined using the proposed method which allows one to measure solubility mole fraction as …
Pleurotus ostreatus volatile aroma compounds identified from fruit-body and from mycelium grown in submerged and solid-state cultures
2003
Comparative analyses of volatile aroma compounds of the Pleurotus ostreatus JMO.95 fruit-body and its corresponding mycelium grown in liquid, on agar surface, or on solid support cultures have been carried out by dynamic headspace concentration using GC/MS and GC/sniffing. The aroma of the fruit-body was due essentially to the presence of octan-3-one and, in a lesser extent, to the presence of octan-3-ol. Other compounds, such as oct-l-en-3-ol, oct-l-en, 2-methylbutanol and a-pinene were also present in low concentrations. The comparison of the aromatic spectra of the fruit-body with the aromatic spectra of mycelia obtained under different culture conditions indicated that the main aromatic…
Comparison of Volatile Flavor Compounds Produced by Ten Strains of Penicillium camemberti Thom
1993
Abstract Volatile compounds produced by Penicillium camemberti Thom in a milk culture medium were identified using gas chromatography coupled with mass spectrometry. Volatile compounds were mainly methyl ketones and their corresponding secondary alcohols, fatty acids, and the alcohols 3-methylbutanol, 2-methylpropanol, 3-octanol, and 1-octen-3-ol. Comparison of 10 strains of P. camemberti Thom resulted in their being grouped into 6 aromatic strain groups, This grouping seems to be useful for the selection of strains for cheese making.
Identification and sensory evaluation of the character-impact compounds of goat cheese flavour
1996
1 SUMMARY The volatile compounds of various goat cheeses have been isolated in order to identify the character-impact odorants by a combination of instrumental analyses and sensory studies. Different extraction procedures have been studied in order to obtain a volatile fraction representative of the cheeses. The most representative extract, as determined by sensory evaluation, has been submitted to GC-MS and to GC-olfactometry, using the aroma extract dilution analysis (AEDA) method. The volatile fatty acids have been found to be the most important compounds for the characteristic goat flavour. Among them, branched-chain fatty acids ( e.g. , 4-methyloctanoic and 4-ethyloctanoic) have been f…
Lemon Oils Attenuate the Pathogenicity of Pseudomonas aeruginosa by Quorum Sensing Inhibition
2021
The chemical composition of three Citrus limon oils: lemon essential oil (LEO), lemon terpenes (LT) and lemon essence (LE), and their influence in the virulence factors production and motility (swarming and swimming) of two Pseudomonas aeruginosa strains (ATCC 27853 and a multidrug-resistant HT5) were investigated. The main compound, limonene, was also tested in biological assays. Eighty-four compounds, accounting for a relative peak area of 99.23%, 98.58% and 99.64%, were identified by GC/MS. Limonene (59–60%), γ-terpinene (10–11%) and β-pinene (7–15%) were the main compounds. All lemon oils inhibited specific biofilm production and bacterial metabolic activities into biofilm in a dose-dep…
Seasonal variations of antimicrobial activity and chemical composition of essential oils extracted from three Citrus limon L. Burm. cultivars
2014
In order to investigate the seasonal variations of antimicrobial properties and chemical composition of essential oils (EOs), three different cultivars of Citrus limon L. Burm. spp. (Femminello Santa Teresa, Monachello and Femminello Continella) were collected at 6-week intervals, from December 2012 to April 2013, for a total of four harvests. The EOs were extracted from lemon peel by hydro-distillation. The antimicrobial activity, tested by paper disc diffusion method, was evaluated against common food-related pathogenic bacteria (Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica and Enterobacter spp.). EOs were more effective against Gram-positive than Gram-negative bacte…
Effect of storage period under variable conditions on the chemical and physical composition and colour of Spanish refrigerated orange juices
2005
The effects of the physicochemical and quality characteristics of various minimally pasteurized refrigerated orange Spanish juices and their changes with storage time and temperature were investigated. Essential oils, acidity, conductivity, diacetyl index, hydroxymethylfurfural, formol index, viscosity and ascorbic acid varied with storage time more significantly at 10 degrees C than at 4 degrees C. Density, colour and pectinmethylesterase did not vary at 4 degrees C. Some of the parameters could be used as indicators of quality loss or spoilage of the juices. The degradation kinetics of the concentration of remaining ascorbic acid against time follows a straight line whose slope indicates …