Journal of Medicinal Materials, 2019, Vol. 24, No. 3 (pp.138 - 144)
LARGE - SCALE DECAFFEINATION OF GREEN TEA USING
SUPERCRITICAL CARBON DIOXIDE
Tran Trong Bien*, Le Thi Bao Ngoc, Bui Thi Thuy Luyen, Nguyen Van Han
Hanoi University of Pharmacy, Vietnam
*Corresponding author: firstname.lastname@example.org
(Received November, 05th, 2018)
Large - Scale Decaffeination of Green Tea Using Supercritical Carbon Dioxide
Large-scale decaffeination from green tea leaves using supercritical carbon dioxide (SC-CO2) was conducted. Experimental conditions were carefully optimized to selectively remove a large amount of caffeine while to remain a large amount of EGCG (a principal catechin in green tea leaf). At 60oC extraction temperature, 300 bar pressure, 50 g/min SC-CO2 flow rate, 7 hours extraction time and 2% of 96%(v/v) ethanol as a cosolvent, the caffeine removal yield was 75.30% while the EGCG extraction yield was 35.83%, resulting in caffeine/EGCG extraction selectivity of 2.10. The extraction results using SC-CO2/96% ethanol were compared with conventional liquid solvent extraction using water or 96% ethanol. The selectivity of caffeine/EGCG extraction with water was 1.30 and that with 96% ethanol was 0.78. Thus SC-CO2 extraction with 96% ethanol as a cosolvent is potential for the selective removal of caffeine from the green tea.
Keywords: Decaffeination, Tea, Supercritical carbon dioxide, Extraction.
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