Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/34047
DC FieldValueLanguage
dc.contributor.authorChen, P.Y.en_US
dc.contributor.author張傑明zh_TW
dc.contributor.authorTu, Y.X.en_US
dc.contributor.authorWu, C.T.en_US
dc.contributor.authorJong, T.T.en_US
dc.contributor.authorChang, C.M.J.en_US
dc.contributor.author鍾婷婷zh_TW
dc.date2004zh_TW
dc.date.accessioned2014-06-06T07:47:05Z-
dc.date.available2014-06-06T07:47:05Z-
dc.identifier.issn0021-8561zh_TW
dc.identifier.urihttp://hdl.handle.net/11455/34047-
dc.description.abstractThis study investigates a semicontinuous hot pressurized fluid extraction process and the scavenging activity on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical of the extract from Taiwan yams (Dioscorea alata). Liquid-liquid extractions were preliminarily employed to generate six fractions, initially extracted by ethanol. Then, the aqueous solution of dried crude ethanol extract was sequentially fractionated by hexane, chloroform, ethyl acetate, and n-butanol. The EC50 value was defined as the UV absorption of DPPH concentrations sufficiently decreased to 50% of the original value. It was found that all peel portions have a better effect on scavenging of the DPPH free radical than meat portions, especially for the ethyl acetate partition of the peel portion of Tainung #2 yam. Its EC50 value (14.5 mug mL(-1)) was even lower than that of ascorbic acid (21.4 mug mL(-1)). Furthermore, semicontinuous hot pressurized ethanol was superior to hot pressurized water in extracting the compound scavenging the DPPH radical from the Purpurea-Roxb peel. The recovery of four unknown compounds corresponded to the scavenging ratio of DPPH free radical in the hot pressurized ethanol extract. Finally, three-level and four-factor experimental design revealed that ethanol ratio and temperature were the most effective factors in order. Conditions of 80% of aqueous ethanol, 20.0 kg/kg solid ratio, 180 psig (1.342 MPa), and 100degreesC were preferred to extract those antioxidants from the yam peel.en_US
dc.language.isoen_USzh_TW
dc.relationJournal of Agricultural and Food Chemistryen_US
dc.relation.ispartofseriesJournal of Agricultural and Food Chemistry, Volume 52, Issue 7, Page(s) 1945-1949.en_US
dc.relation.urihttp://dx.doi.org/10.1021/jf0351826en_US
dc.subjectDioscorea alataen_US
dc.subjectDPPH free radicalen_US
dc.subjecthot pressurized wateren_US
dc.subjectexperimentalen_US
dc.subjectdesignen_US
dc.subjectantioxidant activityen_US
dc.subjectphenolic-compoundsen_US
dc.subjectsubcritical wateren_US
dc.subjectplant-extractsen_US
dc.titleContinuous hot pressurized solvent extraction of 1,1-diphenyl-2-picrylhydrazyl free radical scavenging compounds from Taiwan yams (Dioscorea alata)en_US
dc.typeJournal Articlezh_TW
dc.identifier.doi10.1021/jf0351826zh_TW
item.openairecristypehttp://purl.org/coar/resource_type/c_18cf-
item.openairetypeJournal Article-
item.cerifentitytypePublications-
item.fulltextno fulltext-
item.languageiso639-1en_US-
item.grantfulltextnone-
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