naa a22 4500 510724825 CHVBK 20180411082931.0 cr unu---uuuuu 180411e20130901xx s 000 0 eng 10.1007/s11947-012-0891-9 doi (NATIONALLICENCE)springer-10.1007/s11947-012-0891-9 Optimization of Ultrahigh-Pressure Extraction of Polyphenolic Antioxidants from Green Tea by Response Surface Methodology [Elektronische Daten] [Jun Xi, Baishu Wang] A new extraction technique, ultrahigh-pressure extraction, was used to obtain antioxidants from green tea. The response surface methodology was employed to optimize the extraction process. The effects of ethanol concentration (x 1, 33.2-66.8%), pressure (x 2, 281.8-618.2MPa), and liquid/solid ratio (x 3, 11.6-28.4ml/g) on the total phenolic content (y 1) and α,α-diphenyl-β-picrylhydrazyl free radical scavenging activity (y 2) were investigated. Analysis of variance showed that second-order polynomial models produced a satisfactory fitting of the experimental data with regard to total phenolic content (R 2 = 0.9996, P < 0.0001) and antioxidant capacity (R 2 = 0.9986, P < 0.0001). The optimal condition determined was as follows: ethanol concentration, 50%; pressure, 490MPa; and liquid/solid ratio, 20ml/g. Under this condition, the maximum total phenolic content and antioxidant activity of 583.8 ± 0.9mg/g dry weight and 85.6 ± 0.7% could be achieved, respectively, which were well matched with the predicted value. Springer Science+Business Media, LLC, 2012 Ultrahigh-pressure extraction nationallicence Response surface methodology nationallicence Total phenolic content nationallicence Antioxidant activity nationallicence Green tea nationallicence Xi Jun School of Chemical Engineering, Sichuan University, 610065, Chengdu, China aut Wang Baishu School of Chemical Engineering, Sichuan University, 610065, Chengdu, China aut Food and Bioprocess Technology Springer US; http://www.springer-ny.com 6/9(2013-09-01), 2538-2546 1935-5130 6:9<2538 2013 6 11947 https://doi.org/10.1007/s11947-012-0891-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11947-012-0891-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Xi Jun School of Chemical Engineering, Sichuan University, 610065, Chengdu, China aut NATIONALLICENCE 700 1- Wang Baishu School of Chemical Engineering, Sichuan University, 610065, Chengdu, China aut NATIONALLICENCE 773 0- Food and Bioprocess Technology Springer US; http://www.springer-ny.com 6/9(2013-09-01), 2538-2546 1935-5130 6:9<2538 2013 6 11947 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer