TY  - JOUR
TI  - Sequential Green Extraction of Caffeine and Catechins from Green Tea
AB  - Separation of caffeine and catechins from tea extracts usuallyrequires conventional liquid-liquid extraction employing chloroform. Thiswork was planned to improve a green extraction technique to distunguish theseimportant chemicals from green tea. Extraction of caffeine and catechins fromTurkish green tea firstly employing MAE, and then to separate thesecompounds from each other using a SFE method were purpose of this study.Microwave assisted extraction was applied to extract tea components fromgreen tea then i) conventional liquid-liquid extraction or ii) supercritical carbondioxide fluid extraction (SFE) method was charged with the effective separationof caffeine and catechins. Initially, an ethanol: water mixture was used in a closemicrowave system under the particuler extraction situations of green teasamples (fresh, frozen or dried) picked up in three collection periods (first,second and third collection periods). MAE of tea samples was exerted under acontrolled 600 W microwave power for 4 min irradiation time at 80 Ctemperature. Then MAE crude aqueous extract was divided in to two portions.The first portion was fractionated first with chloroform to distunguish caffeinethen ethyl acetate for catechins. Caffeine and catechins were successfullyseparated. Second portion was freeze-dried and obtained lyophilized solid wasused for SFE. Caffeine (3.68% extract yield) was successfully separated fromcatechins with SFE at 250 bar and 60°C for 180 min. Constituents of the extractswere determined (caffeine and four catechins namely EGC, EC, C, EGCG) byHPLC to evaluate the effectiveness of the separation.
AU  - SERDAR, GÖNÜL
AU  - SÖKMEN, Münevver
AU  - Demir Özer, Ezgi
DO  - 10.21448/ijsm.629151
PY  - 2019
JO  - International Journal of Secondary Metabolite
VL  - 6
IS  - 3
SN  - 2148-6905
SP  - 283
EP  - 291
DB  - TRDizin
UR  - http://search/yayin/detay/334158
ER  -