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Kinetics of Supercritical Fluid Extraction of Carotenoids from Microalgae and Plants.
Sovová, Helena
This contribution summarizes previous results of our analysis of data on the supercritical fluid extraction of carotenoids from microalgae, adds comparison of the mathematical model with newly available experimental data, and applies the model on CO2 extraction of carotenoids from different plants, where equivalent extraction mechanisms are supposed to be valid.
Plný tet: SKMBT_C22018100509360 -  PDF
Plný text: content.csg - PDF
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Supercritical Fluid Extraction of Eucalyptus Volatile Oil in View of Thermodynamic Modelling.
Sovová, Helena ; Stateva, R.P. ; Topiař, Martin
The aim of this contribution is to determine this relationship in the case of eucalyptus oil. The oil from the leaves of Eucalyptus grandis L., which was selected for experiments, is rich in a monoterpene alfa-pinene, a monoterpene oxide 1,8-cineole, a sesquiterpene aromadendrene, and a sesquiterpene alcohol globulol. The composition of saturated vapour phase in volatile oil+CO2 system was measured by sampling the extract from either milled dry leaves or essential oil on inert carrier, using a sufficiently large solvent residence time. Gas chromatography was used to analyse the composition of the samples, leaves, and essential oil. The extraction pressure and temperature were varied in the region of scCO2 with relatively low density, where the solvent selectivity is more pronounced. The experimental results were used to determine the temperature dependence of the parameters of thermodynamic model for the studied system.
Plný tet: SKMBT_C22016090211381 - PDF
Plný text: content.csg - PDF
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Comparison of Extraction Methods for Isolation of 20-Hydroxyecdysone from Leuzea carthamoides
Machalová, Zdeňka ; Sajfrtová, Marie ; Sovová, Helena ; Bártlová, Milena
This work is focused on the extraction of 20-HE from roots and seeds of Leuzea carthamoides using SFE, PLE and Soxhlet extraction. The SFE and PLE conditions (pressure, temperature, type and concentration of solvent, extraction time) were optimized to improve extraction yields and concentrations of 20-HE in extracts. These methods were compared with a conventional Soxhlet-type extraction. The SFE experiments were carried out at temperatures from 40°C to 60°C, pressures from 30 to 65 MPa and with addition of 5-20% of co-solvent (ethanol, methanol and acetone). PLE with ethanol, methanol and acetone was made at temperatures from 70°C to 100°C, pressures from 7 to 20 MPa and extraction time from 5-15 min. Soxhlet extraction with ethanol was used to evaluate the total content of 20-HE in roots and seeds. The concentration of 20-HE in extracts was determined by HPLC.
Plný tet: SKMBT_C22014082908303 - PDF
Plný text: content.csg - PDF
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Extraction Kinetics and Insecticidal Activity of Volatile Components Isolatedfrom rue by Supercritical CO2.
Sajfrtová, Marie ; Karban, Jindřich ; Sovová, Helena ; Pavela, R.
The aim of the work was to describe the SFE of volatile components from rue and to analyse their insecticidal effects. The objectives consisted in: (a) optimizing the SFE condition (pressure, temperature, extraction time, use of additional separator and concentration of modifier in CO2),investigating their effect on the yield, concentration volatiles in extract and the insecticidal activity, determination of the SFE kinetics of major components in the rue extracts and comparing the SFE with hydrodistillation and maceration.
Plný tet: SKMBT_C22014090110391 - PDF
Plný text: content.csg - PDF
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