Influence of processing stages on antimutagenic and antioxidant potentials of rooibos tea

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dc.contributor.authorStandley L.
dc.contributor.authorWinterton P.
dc.contributor.authorMarnewick J.L.
dc.contributor.authorGelderblom W.C.A.
dc.contributor.authorJoubert E.
dc.contributor.authorBritz T.J.
dc.contributor.authorStandley L.
dc.contributor.authorWinterton P.
dc.contributor.authorMarnewick J.L.
dc.contributor.authorGelderblom W.C.A.
dc.contributor.authorJoubert E.
dc.contributor.authorBritz T.J.
dc.date.accessioned2011-05-15T15:56:53Z
dc.date.accessioned2011-05-15T15:56:53Z
dc.date.available2011-05-15T15:56:53Z
dc.date.available2011-05-15T15:56:53Z
dc.date.issued2001
dc.date.issued2001
dc.description.abstractThe antimutagenic and antioxidant potentials of rooibos (Aspalathus linearis) tea samples, collected from each of its major processing stages, were evaluated according to the Salmonella typhimurium mutagenicity test and the hydrogen donating ability and superoxide anion radical scavenging assays, respectively. Ten random samples were collected before and after fermentation, as well as after sun-drying, sieving, and steam pasteurization. Results indicated that the fermented tea had a significantly (P < 0.05) lower antimutagenic and antioxidant potential than the unfermented tea. Of the different processing stages, the most significant reduction in the antimutagenic and antioxidant property of the tea was found during the "fermentation" step. Sun-drying, sieving, and steam pasteurization also reduced the antimutagenic potential of the tea, although not to the same extent as the first processing step. The hydrogen donating ability was significantly increased after steam pasteurization in comparison to those of fermented and sun-dried tea. Pasteurization did not affect superoxide anion radical scavenging in comparison to fermented tea. Differences seem to exist in the antimutagenicity and antioxidant potencies of the tea sampled at the various stages during processing. A possible role of tea polyphenols in the antimutagenic and antioxidant activities of the tea is suggested as processing caused a significant reduction in the total polyphenolic content.
dc.description.abstractThe antimutagenic and antioxidant potentials of rooibos (Aspalathus linearis) tea samples, collected from each of its major processing stages, were evaluated according to the Salmonella typhimurium mutagenicity test and the hydrogen donating ability and superoxide anion radical scavenging assays, respectively. Ten random samples were collected before and after fermentation, as well as after sun-drying, sieving, and steam pasteurization. Results indicated that the fermented tea had a significantly (P < 0.05) lower antimutagenic and antioxidant potential than the unfermented tea. Of the different processing stages, the most significant reduction in the antimutagenic and antioxidant property of the tea was found during the "fermentation" step. Sun-drying, sieving, and steam pasteurization also reduced the antimutagenic potential of the tea, although not to the same extent as the first processing step. The hydrogen donating ability was significantly increased after steam pasteurization in comparison to those of fermented and sun-dried tea. Pasteurization did not affect superoxide anion radical scavenging in comparison to fermented tea. Differences seem to exist in the antimutagenicity and antioxidant potencies of the tea sampled at the various stages during processing. A possible role of tea polyphenols in the antimutagenic and antioxidant activities of the tea is suggested as processing caused a significant reduction in the total polyphenolic content.
dc.description.versionArticle
dc.description.versionArticle
dc.identifier.citationJournal of Agricultural and Food Chemistry
dc.identifier.citation49
dc.identifier.citation1
dc.identifier.citationJournal of Agricultural and Food Chemistry
dc.identifier.citation49
dc.identifier.citation1
dc.identifier.issn218561
dc.identifier.issn218561
dc.identifier.other10.1021/jf000802d
dc.identifier.other10.1021/jf000802d
dc.identifier.urihttp://hdl.handle.net/10019.1/10092
dc.identifier.urihttp://hdl.handle.net/10019.1/10092
dc.subjectplant extract; polyphenol derivative; scavenger; superoxide; unclassified drug; Ames test; antioxidant activity; article; aspalathus linearis; controlled study; desiccation; fermentation; food analysis; food handling; mutagen testing; nonhuman; pasteurization; Salmonella typhimurium; tea; water vapor; 2-Acetylaminofluorene; Antimutagenic Agents; Antioxidants; Desiccation; Fermentation; Food Handling; Free Radical Scavengers; Mutagenicity Tests; Steam; Superoxides; Tea; Aspalathus linearis; Salmonella typhimurium; Typhimurium
dc.subjectplant extract
dc.subjectpolyphenol derivative
dc.subjectscavenger
dc.subjectsuperoxide
dc.subjectunclassified drug
dc.subjectAmes test
dc.subjectantioxidant activity
dc.subjectarticle
dc.subjectaspalathus linearis
dc.subjectcontrolled study
dc.subjectdesiccation
dc.subjectfermentation
dc.subjectfood analysis
dc.subjectfood handling
dc.subjectmutagen testing
dc.subjectnonhuman
dc.subjectpasteurization
dc.subjectSalmonella typhimurium
dc.subjecttea
dc.subjectwater vapor
dc.subject2-Acetylaminofluorene
dc.subjectAntimutagenic Agents
dc.subjectAntioxidants
dc.subjectDesiccation
dc.subjectFermentation
dc.subjectFood Handling
dc.subjectFree Radical Scavengers
dc.subjectMutagenicity Tests
dc.subjectSteam
dc.subjectSuperoxides
dc.subjectTea
dc.subjectAspalathus linearis
dc.subjectSalmonella typhimurium
dc.subjectTyphimurium
dc.titleInfluence of processing stages on antimutagenic and antioxidant potentials of rooibos tea
dc.titleInfluence of processing stages on antimutagenic and antioxidant potentials of rooibos tea
dc.typeArticle
dc.typeArticle
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