1,721,155 research outputs found
Extraction of volatile fractions and carotenoids from orange and kumquat peel by supercritical carbon dioxide
No full textComparative analysis of the oil and supercritical CO2 extract of Artemisia arborescens L. and Helichrysum splendidum (Thunb.) Less
No full textComparative analysis of the oil and supercritical CO2 extract of Elettaria cardamomum (L.) Maton
No full text
Isolation of Seseli bocconi Guss. subsp. praecox Gamisans (apiaceae) volatile oil by supercritical carbon dioxide extraction
No full textIsolation of the volatile concentrate from dried leaves of Seseli bocconi Guss. subsp. praecox
Gamisans were obtained by supercritical fluid extraction (SFE) with carbon dioxide. Leaves
from different zones of Sardinia (Italy) were collected and treated. Compositions of samples
were analyzed by GC-MS. The volatile concentrate of S. bocconi from Buggerru was found
to contain: himachalol (16.4%), sabinene (14.8%), -phellandrene (8.1%), cis-sabinene hydrate
(4.5%). -Phellandrene (29.2%), undecane (9.6%), -pinene (6.1%) and -guaiene (5.7%) were
the main constituents of the volatile extract of S. bocconi from Carloforte. The volatile concentrate
of S. bocconi of Ogliastra inland, was composed chiefly by -humulene (17.7%),
-himachalene (9.3%), -phellandrene (8.0) and bicyclogermacrene (7.7%). The yields of
extraction were in the range (0.13–0.60%). A comparison with the hydrodistilled oil revealed
in each case a remarkable difference in composition
Comparative analysis of the oil and supercritical CO2 extract of Ridolfia segetum (L) Moris
No full textSupercritical carbon dioxide extraction allowed to obtain the volatile oil of different aerial parts
of Ridolfia segetum (L.) Moris. Extraction conditions were as follows: pressure, 90 bar;
temperature, 50C and carbon dioxide flow, 1⁄41.0 kg h1. Waxes were entrapped in the first
separator set at 90 bar and 10C. The oil was recovered in the second separator working
at 15 bar and 10C. The main components of the flower oil were -phellandrene (19.4%),
terpinolene (20.5%), piperitenone oxide (11.6%), -phellandrene (8.2%), (Z)--ocimene
(7.8%), myristicin (7.5%) and p-cymene (4.4%). The comparison with the hydrodistilled
(HD) oil reveal that the significative difference was the content of sesquiterpenes which are
higher in the supercritical fluid extraction (SFE) products. Collection of samples at different
extraction times during supercritical extraction, allowed to monitor the change of the oil
composition. Lighter compounds, as hydrocarbon monoterpenes, were extracted in shorter
times than the heavier hydrocarbon and oxygenated sesquiterpenes. The oil from the steams
was characterized by a high content of -phellandrene (12.9%), terpinolene (11.6%), myristicin
(11.0%), p-cymene (9.9%), -phellandrene (8.2%) and (Z)--ocimene (6.0%) while the main
components of the fruits were found to be myristicin (70.8%), piperitenone oxide (19.9%) and
dill apiole (4.2%)
Calorimetric Study Of The Heteroproximity Effect In Mixtures Containing Chloroalkylbenzenes.
No full textChemical composition of the oil and supercritical CO2 extract of Schinus molle L.
No full textSupercritical carbon dioxide extraction allowed Schinus molle L. volatile oil to be obtained. Extraction conditions were as follows: pressure, 90 bar; temperature, 50 °C, carbon dioxide flow, Φ = 1.0 kg/h. Waxes were entrapped in the first separator set at 90 bar and -10 °C. The oil was recovered in the second separator, working at 15 bar and 10 °C. The main components were α-phellandrene (26.5%), limonene + β-phellandrene (21.0%), elemol (10.8%) and α-eudesmol (6.1%). Comparison with the hydrodistilled oil (HD) did not reveal any large difference, whereas the significant difference between the SFE and SD oils was the content of sesquiterpenes, which is higher in the SFE products. Collection of samples at different extraction times during supercritical extraction allowed changes of the oil composition to be monitored. Lighter compounds, as hydrocarbon monoterpenes, were extracted in shorter times than the heavier hydrocarbon and oxygenated sesquiterpenes
Supercritical fluid extraction and fractionation of essential oils and related products from natural matrices
No full textCalorimetric study of nitro group/solvent interactions. Comparison with DISQUAC predictions
No full textA flow microcalorimeter, model 2277-LKB, has been used to determine excess enthalpies, H(E), at 298.15 K, for liquid mixtures containing ethanenitrile, propanenitrile, butanentrile, or pentanenitrile + benzene or tetrachloromethane. These experimental results together with the literature data on thermodynamic properties of alkanenitrile + benzene or tetrachloromethane mixtures have been interpreted in terms of the dispersive quasi-chemical (DISQUAC) group contribution model. Two sets of structure-dependent interaction parameters, for the nitrile group/aromatic and for the nitrite group/tetrachloromethane contacts, have been obtained. The model provides a fairly consistent description of the excess Gibbs energy, G(E), excess enthalpy, H(E), and of activity coefficients at infinite dilution, gamma(infinity)(i), of the considered mixtures
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