Supercritical fluid extractive fractionation--study of the antioxidant activities of propolis

doi:10.1016/j.foodchem.2003.09.031

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Please use this identifier to cite or link to this item: http://nhuir.nhu.edu.tw/handle/987654321/25044

Title:	Supercritical fluid extractive fractionation--study of the antioxidant activities of propolis
Authors:	余哲仁;Yu, Zer-Ran;Wang, Be-Jen;Lien, Yen-Hui
Contributors:	自然生物科技學系
Keywords:	Propolis;Supercritical fluid extractive fractionation;Antioxidant activities
Date:	2004-06
Issue Date:	2017-07-11 16:35:50 (UTC+8)
Abstract:	Propolis was mixed with ethanol at a ratio of 1:10 (v/w) for 24 h to yield propolis ethanol extract (E). Extract E was further fractionated with supercritical carbon dioxide (SC-CO₂) into four fractions (R, F1, F2 and F3). To evaluate the selectivity of the fractionation, extracts corresponding to four fractions were characterized in terms of total flavonoid contents, antioxidant abilities and antioxidant mechanisms. Experimental results indicated that fractionation altered the composition distributions of fractions, e.g., by reducing total flavonoid contents. The antioxidant ability, metal chelating capacity, reducing power, and scavenging capacity of DPPH, O₂·−or ·OH radicals of propolis extract and fractions increased with propolis concentrations. The effects of scavenging on DPPH of propolis extract and fractions, at 2 mg/ml were R (93%), E (75%), F1 (56%), F2 (47%), and F3 (27%). At a concentration of 1 mg/ml, propolis fractions scavenged O₂·− by over 73% and all the fractions trapped around 65% of the ·OH groups. This in vitro study of antioxidant effects showed that R and F1 were the best fractions, followed by F2.
Relation:	Food Chemistry vol. 86, no. 2 pp.237-243
Appears in Collections:	[Department of Natural Biotechnology] Periodical Articles

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