-
Isolation of active ingredients from green tea (Fanning Bellas, China) [Elektronski vir]Perva, Amra ; Škerget, Mojca ; Knez, ŽeljkoValuable active ingredients in green tea leaves (Camellia sinensis) are polyphenolic compounds, which are found in the range from 5 to 30 wt. % in raw material and are usually isolated by solvent ... extractions. Tea leaves also contain caffeine, an alkaloid, which contributes to stimulant properties of tea in addition to positive pharmacological properties caused by polyphenolic compounds, which act as natural antioxidants. In the frame of presented study, lower grade green tea leaves (variety Fanning Belas, China) used in teabags were extracted with various solvents (acetone, ethanol, methanol, acetonitrile, water) employing different extraction conditions of temperature,time and ratio material:solvent. Raw extracts were analysed on major catechins (EC, ECG, EGC, EGCG), caffeine, three flavonols (myricetin, kaempherol, quercetin), and proanthocyanidins. Raw material was found to contain 190.8 g of major catechins and 36.0 g of caffeine and 5.2 g of flavonols per kg of dry material. The content of major catechins in green tea extracts obtained with different aqueous solvents varied from 280 to 580 g catechins/kg extract, while content of caffeine in extract was in average 75g/kg. Content of the three flavonols and proanthocyanidins was in the range from 6-20 g/kg and 12-19 g/kg, respectively. Different extraction procedures with water were also investigated and optimal conditions determined: maximum reached extraction efficiency of catechins with water was obtained at 80°C after 20 min (97 %) and at 95°C after 10 min of extraction (90 %). Decaffeinated green tea leaves, which were obtained by high-pressure extraction with CO2, were extracted at optimal conditions and a decaffeinated green tea extract rich in major catechins was obtained.Vir: CHISA 2004 [Elektronski vir] : CD-ROM of full texts (8 str. (0611))Vrsta gradiva - prispevek na konferenciLeto - 2004Jezik - angleškiCOBISS.SI-ID - 8959766
Avtor
Perva, Amra |
Škerget, Mojca |
Knez, Željko
Teme
kemijska procesna tehnika |
visokotlačna tehnologija |
superkritični fluidi |
CO2 |
ekstrakcija |
zeleni čaj |
katehini |
optimalni pogoji ekstrakcije |
kofein |
chemical processing |
high pressure technology |
supercritical fluids |
CO2 |
extraction |
catechins |
optimal extraction conditions |
caffeine |
solvent extraction
![loading ... loading ...](themes/default/img/ajax-loading.gif)
Vnos na polico
Trajna povezava
- URL:
Faktor vpliva
Dostop do baze podatkov JCR je dovoljen samo uporabnikom iz Slovenije. Vaš trenutni IP-naslov ni na seznamu dovoljenih za dostop, zato je potrebna avtentikacija z ustreznim računom AAI.
Leto | Faktor vpliva | Izdaja | Kategorija | Razvrstitev | ||||
---|---|---|---|---|---|---|---|---|
JCR | SNIP | JCR | SNIP | JCR | SNIP | JCR | SNIP |
Baze podatkov, v katerih je revija indeksirana
Ime baze podatkov | Področje | Leto |
---|
Povezave do osebnih bibliografij avtorjev | Povezave do podatkov o raziskovalcih v sistemu SICRIS |
---|---|
Perva, Amra | 21690 |
Škerget, Mojca | 11865 |
Knez, Željko | 02619 |
Izberite prevzemno mesto:
Prevzem gradiva po pošti
Obvestilo
Gesla v Splošnem geslovniku COBISS
Izbira mesta prevzema
Mesto prevzema | Status gradiva | Rezervacija |
---|
Prosimo, počakajte trenutek.