|
|
Supercritical Fluid Fractionation for 20-Hydroxyecdysone Enrichment in Leuzea carthamoides Extract
Sajfrtová, Marie ; Maščeník, J. ; Sovová, Helena ; Bártlová, Milena
Supercritical fluid extraction of 20-hydroxyecdysone (20-HE) using pure and modified carbon dioxide from seeds of Leuzea carthamoides was studied. The effect of operation conditions on the yields of whole extract and its minor component 20-HE was analysed in a series of experiments at pressures from 30 MPa to 60 MPa, temperatures from 40 °C to 80 °C and modifier (ethanol, methanol and acetone) concentrations in CO2 0-19 wt. %. The consecutively collected extract fractions were analysed using HPLC. The efficiency of SFE in terms of 20-HE concentration in extract and yield was compared with the efficiency of Soxhlet extraction with ethanol.
|
|
|
Enrichment of Supercritical Extracts in beta-Sitosterol by Fractionation Process
Rochová, Kristina ; Sovová, Helena ; Sajfrtová, Marie ; Bártlová, Milena
The aim of this contribution was to use the extraction with supercritical CO2 coupled with fractionation of extract for preparation of extracts rich in beta-sitosterol. Phytosterols have been proved to lower serum cholesterol levels in humans and to have other benefit for human health. Supercritical extraction is a green method to separate such compounds from plants. Sea buckthorn seeds and sunflower seeds were extracted and a mathematical model was applied to determine separation factor of beta-sitosterol as minor component of extract. According to the obtained results, conditions of fractionation were set up. The most important enrichment of a part of extract from seeds with beta-sitosterol was achieved with fractionation in two separators (first separator kept at 15MPa and 50°C) and subsequent fractionation in time at the output of the second separator.
|
|
| |
|
|
Superkritická extrakce beta-sitosterolu ze slupek a listů rakytníku řešetlákového
Sajfrtová, Marie ; Sovová, Helena ; Bártlová, Milena
Extraction of beta-sitosterol with supercritical carbon dioxide from sea buckthorn pulp and leaves, a by-product of production of sea buckthorn juice, was studied. The effect of operation conditions on the yields and solubility of whole extract and its minor component beta-sitosterol was analysed in a series of experiments at pressures from 15 MPa to 28 MPa and temperatures 40 °C and 60 °C. The consecutively collected extract samples were analysed using HPLC. The selectivity of beta-sitosterol to major component was determined. The content of beta-sitosterol in both plant materials was obtained using Soxhlet extraction with hexane.
|
|
| |
|
| |
|
|
Supercritical Fluid Extraction and Characterisation of Urtica Dioica L. Leaves Pigments
Sajfrtová, Marie ; Sovová, Helena ; Bártlová, Milena ; Opletal, L.
Extraction and fractionation of green and yellow pigments from stinging nettle leaves was studied using ethanol-modified carbon dioxide as a solvent. The extracts were analysed by means of HPLC and RP-HPLC systems. The effect of operation conditions was analysed in a series of experiments at pressures from 20 MPa to 28 MPa, temperatures between 25 °C and 60 °C, and ethanol concentration in CO2 between 0 and 7.4 wt.%. The main result was that the best conditions for the supercritical fluid extraction of pigments were ethanol concentration in CO2 4.5 - 7.4 wt.%, temperature 40°C and pressure 28MPa and that degradation of pigments was eliminated with decrease of temperature of micrometer valve and addition of small amount of antioxidant to ethanol.
|
|
| |
|
| |
|
| |
guest ::
RSS feed.