1,721,242 research outputs found
Wild Harenna coffee: flavour profiling from the bean to the cup
Full text linkAs one of the last places where coffee grows spontaneously, the Harenna forest (Ethiopia) is the origin of the coffee analysed in this study. The analysis of the volatile emission of each processing phase evaluates the chemical fingerprint of the reactions taking place at each stage, leading to the final aroma. The green beans mainly emit non-terpene esters and alkanes. Once the roasting begins, monoterpenes are the main class until 160 °C: at this point, 2,6-dimethylpyrazine prevails in the headspaces, as main product of the Maillard reactions. This compound, with its sweet and nut-like aroma, is also detected in the brewed coffee. The shed silverskins are rich in methyl chavicol and retain the monoterpenes on the beans: as these compounds are important aroma contributors, the removal of the silverskins prior to roasting seems non-advisable. The grinding of the samples breaks the matrices and leads to drastic changes in the volatile emissions
The Determinants of Tax Aggressiveness in Family Firms: An Investigation of Italian Private Family Firms
No full textCharacterization of volatile metabolites of Tithonia diversifolia(Hemsley) A. gray leaves and flowers
No full textThe leaf and floral essential oils of Tithonia diversifolia (Hemsley) A. Gray (Asteraceae) were analyzed for composition by means of gas chromatography-mass spectrometry (GC-MS). Forty-two constituents were identified in the leaf and floral oils, accounting for 97.2% and 95.3% of the total composition, respectively. Germacrene D (46.0%), β-caryophyllene (12.2%), and methyl carvacrol (9.8%) were the prominent components of the leaf oil, while the main constituents of the floral oil consisted of germacrene D (32.5%), α-pinene (7.5%), and β-caryophyllene (6.6%
Spontaneous emission of volatiles from the male flowers of the early-branching angiosperm Amborella trichopoda
No full textMain conclusion: Volatile emissions were detected for the first time in male flowers of the early-branching angiosperm Amborella trichopoda, suggesting a defensive and attractive double role of these compounds. Abstract: Flower volatile emissions were detected for the first time in male flowers of the early-branching angiosperm Amborella trichopoda. A mixture of seven volatile compounds is found in flower buds, with limonene resulting as the most abundant compound (67%). Further five volatiles are found in freshly opened flowers, with limonene contributing to 31.7%, followed by decanal (15.5%) and by ethyl octanoate (10.3%). While monoterpene hydrocarbons dominate in flower buds (73.6%), their emission in freshly opened flowers is reduced to 41.1%, while non-terpene derivatives are the most abundant (47.1%) chemical class. These compounds, emitted in low amounts, are possibly linked to pollen, which is considered the only reward offered for insect-pollination in this species
Oncoba spinosa leaf and Morus mesozygia leaf and stem bark essential oils
No full textThe essential oils of Oncoba spinosa leaf and Morus mesozygia leaf and stem bark were extracted using hydro distillation and analyzed by means of Gas chromatography (GC) and GC coupled with mass spectrometry (GC-MS). The yields of the essential oils were; 0.50 %, 0.165 % and 0.456 % respectively for Oncoba spinosa leaf, Morus mesozygia leaf and stem oil. A total of twenty eight, thirty four and twenty compounds representing 92.0%, 92.0% and 96.9% of the total oil contents were identified, respectively from the leaf of O. spinosa, leaf and stem oil of M. mesozygia. Leaf oil of O. spinosa contained linalool (22.1 %), β – caryophyllene (18.7 %), caryophyllene oxide (10.6 %) and pentadecanal (5.6 %) as the main constituents. M. mesozygialeaf oil was dominated with β – elemene (11.7 %), (E) –β- ionone (12.4 %), α- selinene (5.1 %), germacrene A (6.0 %), δ – cadinene (4.7 %) and spathulenol (7.4 %) while M. mesozygia stem oil had 2 –dodecanone (77%) and hexahydrofarnesylacetone (13 %) as its main constituents
Essential oil composition of Terminalia ivorensis A. Chev. flowers from Northern Nigeria
Full text linkIn the present study, the volatile compounds identified in the essential oil from the flowers of Terminalia ivorensis A. Chev (Combretaceae) collected from Kaduna, Northern Nigeria, are reported. Essential oils were obtained using hydrodistllation in a Clevenger- type apparatus. The yield of the light yellow oil was found to be 0.22% (v/w, dry weight basis). The content and composition of the oil were analyzed by gas chromatography (GC-FID) and gas chromatography with electron impact mass spectrometry (GC-MS). The main compounds of the oil were δ-3-carene (29.4%) and α-pinene (20.9%). To the best of our knowledge, this is the first report on the essential oil constituents of any part of T. ivorensis
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