中国科技论文在线

上传时间

2005年03月04日

【期刊论文】Antioxidant Activity of Extracts of Black Sesame Seed (Sesamum indicum L.) by Supercritical Carbon Dioxide Extraction

胡秋辉， QIUHUI HU， †， JUAN XU， ‡， SHUBING CHEN， AND FANGMEI YANG*

J. Agric. Food Chem. 2004, 52, 943-947，-0001，（）：

-1年11月30日

摘要

activities of extracts derived from sesame seed by supercritical carbon dioxide (SC-CO2) extraction and by n-hexane were determined using R,R-diphenyl-â-picylhydrazyl (DPPH) radical scavenging and linoleic acid system methods. The highest extracted yield was given at 35℃, 40MPa, and a CO2 flow rate of 2.5mL min-1 by an orthogonal experiment. The yields of extracts increased with increasing pressure, and yields at 40 and 30MPa were higher than that by solvent extraction at 46.50%. Results from the linoleic acid system showed that the antioxidant activity follows the order: extract at 3℃, 20MPa>BHT>extract at 55℃, 40MPa>extract at 55℃, 30MPa>Trolox>solvent extraction>R-tocopherol. The SC-CO2 extracts exhibited significantly higher antioxidant activities comparable to that by n-hexane extraction. The extracts at 30MPa presented the highest antioxidant activities assessed in the DPPH method. At 20MPa, the EC50 increased with temperature, which indicated that the antioxidant activity was decreased in a temperature-dependent manner. The significant differences of antioxidant activities were found between the extracts by SCCO2 extraction and n-hexane. However, no significant differences were exhibited among the extracts by SC-CO2 extraction. The vitamin E concentrations were also significantly higher in SC-CO2 extracts than in n-hexane extracts, and its concentrations in extracts corresponded with the antioxidant activity of extracts.

Antioxidant activity， sesame， seed， black extracts

50浏览
0点赞
0收藏
0分享
669下载
0

引用

上传时间

2005年03月04日

【期刊论文】Evaluation of Antioxidant Potential of Aloe vera (Aloe barbadensis Miller) Extracts

胡秋辉， YUN HU， †， JUAN XU， ‡， AND QIUHUI HU*

J. Agric. Food Chem. 2003, 51, 7788-7791，-0001，（）：

-1年11月30日

摘要

The polysaccharide and flavonoid concentrations of two-, three-, and four-year-old Aloe vera were determined, and their antioxidant activities were evaluated compared to BHT and R-tocopherol by the DPPH radical scavenging method and the linoleic acid system at 100

Aloe vera， growth period， extract， antioxidant activity

34浏览
0点赞
0收藏
0分享
588下载
0

引用

上传时间

2005年03月04日

【期刊论文】Effect of Selenium on Increasing the Antioxidant Activity of Tea Leaves Harvested during the Early Spring Tea Producing Season

胡秋辉， JUAN XU， †， FANGMEI YANG， LICHENG CHEN， YUN HU， AND QIUHUI HU*

J. Agric. Food Chem 2003, 51, 1081-1084，-0001，（）：

-1年11月30日

摘要

This research was to determine the effect of foliar application of selenium on increasing the antioxidant activity of tea harvested during the early spring tea producing season using a R,R-diphenyl-

Selenium， Se-enriched green tea， antioxidant activity