In this study, we determined how unfermented and fermented rooibos tea (RT and GRT) amounts, tea leaf weight, extraction time, and temperature influence 1, 1-Diphenyl-2-Picrylhydrazyl (DPPH) radical-scavenging activity, and total polyphenol and aspalathin contents. When RT and GRT were obtained through steeping 1.5, 2.5, 5, or 10 g of tea leaves in 500 mL of boiling water for 10 min, the total polyphenol and aspalathin contents and the DPPH radical scavenging activity increased with the increase in the amount of tea leaves used. When 10 g of tea leaves were extracted using 500 mL of boiling water for 10 min, the total polyphenol and aspalathin contents and the DPPH scavenging activity of GRT (about 940 µg/mL, and 5.9 mM ascorbic acid equivalent, respectively) were higher than those of RT (about 760 µg/mL, and 3.6 mM ascorbic acid equivalent, respectively). When 5 g of tea leaves were extracted using 500 mL of boiling water for 15-20 min, the total polyphenol and aspalathin contents and the DPPH scavenging activity of RT and GRT were higher than those extracted in 5-10 min. Notably, we observed almost no difference in the total polyphenol and aspalathin contents of RT and GRT when extracted at 80 °C compared to decocted for 10 min.
"},{"@language":"ja","@value":"本研究では，発酵および非発酵ルイボスティー（RTおよびGRT）の抽出時の茶葉量，時間および温度によるポリフェノール含量および抗酸化活性への影響を調べた．
500 mLの水道水を沸騰させた熱水で茶葉1.5-10 gを10分間浸漬した「お湯出し」条件では，茶葉量は，1,1-ジフェニル-2-ピクリルヒドラジル（DPPH）ラジカル消去活性（抗酸化活性）と正の相関関係示し，茶葉5および10 gのRTと比べて，GRTは半分の茶葉量で同レベルの抗酸化活性を示した．また，茶葉5 gを500 mL熱水で5-20分間お湯出しした場合，RTでは15分以上，GRTでは20分以上浸漬することにより，より効率的にポリフェノールや抗酸化活性を引き出せることが確認された．7 °C，12時間浸漬の「水出し」条件（茶葉5 g/500 mL）では，ポリフェノール量と抗酸化活性はRTでお湯出し5分間，GRTで10-15分間と同程度であることがわかった．RTは茶葉5 g（/500 mL），10分間，70および80 °Cは沸騰を保った沸騰水の抽出「煮出し」と比較して，総ポリフェノールおよびアスパラチン含量，DPPHラジカル消去活性に大きな違いは見られなかった．GRTにおいても80 °Cと沸騰水ではポリフェノールおよびアスパラチン含量に有意な差は認められなかった．本実験で検討した条件では，茶葉量10 g/500 mL，10分間お湯出しは，総ポリフェノール含量（RT：756±9；GRT：939±5 µg/mL），アスパラチン含量（RT：10.6；GRT：363 µg/mL），DPPHラジカル消去活性（RT：3.62；GRT：5.87±0.03 mMアスコルビン酸当量）が最も高い条件であった．また，本研究により，RTおよびGRTは，「お湯出し」および「水出し」でもポリフェノールおよびアスパラチンや抗酸化活性を有することが確認された．
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Res."},{"@language":"ja","@value":"食科工"},{"@language":"en","@value":"JOURNAL OF THE JAPANESE SOCIETY FOR FOOD SCIENCE AND TECHNOLOGY"},{"@language":"en","@value":"NIPPON SHOKUHIN KAGAKU KOGAKU KAISHI"}],"dc:publisher":[{"@language":"en","@value":"Japanese Society for Food Science and Technology"},{"@language":"ja","@value":"公益社団法人 日本食品科学工学会"}],"prism:publicationDate":"2021-02-15","prism:volume":"68","prism:number":"2","prism:startingPage":"84","prism:endingPage":"91"},"reviewed":"false","url":[{"@id":"https://agriknowledge.affrc.go.jp/RN/2010937072"},{"@id":"http://id.ndl.go.jp/bib/031273395"},{"@id":"https://ndlsearch.ndl.go.jp/books/R000000004-I031273395"},{"@id":"https://www.jstage.jst.go.jp/article/nskkk/68/2/68_84/_pdf"},{"@id":"https://search.jamas.or.jp/link/ui/2021210935"}],"availableAt":"2021-02-15","foaf:topic":[{"@id":"https://cir.nii.ac.jp/all?q=rooibos","dc:title":"rooibos"},{"@id":"https://cir.nii.ac.jp/all?q=green%20rooibos","dc:title":"green rooibos"},{"@id":"https://cir.nii.ac.jp/all?q=polyphenol","dc:title":"polyphenol"},{"@id":"https://cir.nii.ac.jp/all?q=aspalathin","dc:title":"aspalathin"},{"@id":"https://cir.nii.ac.jp/all?q=antioxidant%20activity","dc:title":"antioxidant activity"},{"@id":"https://cir.nii.ac.jp/all?q=%E3%83%AB%E3%82%A4%E3%83%9C%E3%82%B9","dc:title":"ルイボス"},{"@id":"https://cir.nii.ac.jp/all?q=%E3%82%B0%E3%83%AA%E3%83%BC%E3%83%B3%E3%83%AB%E3%82%A4%E3%83%9C%E3%82%B9","dc:title":"グリーンルイボス"},{"@id":"https://cir.nii.ac.jp/all?q=%E3%83%9D%E3%83%AA%E3%83%95%E3%82%A7%E3%83%8E%E3%83%BC%E3%83%AB","dc:title":"ポリフェノール"},{"@id":"https://cir.nii.ac.jp/all?q=%E3%82%A2%E3%82%B9%E3%83%91%E3%83%A9%E3%83%81%E3%83%B3","dc:title":"アスパラチン"},{"@id":"https://cir.nii.ac.jp/all?q=%E6%8A%97%E9%85%B8%E5%8C%96","dc:title":"抗酸化"}],"project":[{"@id":"https://cir.nii.ac.jp/crid/1040000781962536960","@type":"Project","projectIdentifier":[{"@type":"KAKEN","@value":"17K00901"},{"@type":"JGN","@value":"JP17K00901"},{"@type":"URI","@value":"https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17K00901/"}],"notation":[{"@language":"ja","@value":"健康長寿に寄与する茶飲料の食欲亢進効果：情動脳機能との関係"},{"@language":"en","@value":"Effects of drinking unfermented and fermented rooibos tea on appetite"}]}],"relatedProduct":[{"@id":"https://cir.nii.ac.jp/crid/1360011143626323584","@type":"Article","relationType":["references"],"jpcoar:relatedTitle":[{"@value":"Use of countercurrent chromatography during isolation of 6-hydroxyluteolin-7-O-β-glucoside, a major antioxidant of Athrixia phylicoides"}]},{"@id":"https://cir.nii.ac.jp/crid/1360011144590408064","@type":"Article","relationType":["references"],"jpcoar:relatedTitle":[{"@value":"Antioxidant Determinations by the Use of a Stable Free Radical"}]},{"@id":"https://cir.nii.ac.jp/crid/1361981469474601984","@type":"Article","relationType":["references"],"jpcoar:relatedTitle":[{"@value":"Hypoglycemic effect of aspalathin, a rooibos tea component from Aspalathus linearis, in type 2 diabetic model db/db mice"}]},{"@id":"https://cir.nii.ac.jp/crid/1361981470702759680","@type":"Article","relationType":["references"],"jpcoar:relatedTitle":[{"@value":"Effect of Heat on Aspalathin, Iso-orientin, and Orientin Contents and Color of Fermented Rooibos (Aspalathus linearis) Iced Tea"}]},{"@id":"https://cir.nii.ac.jp/crid/1362544420413113088","@type":"Article","relationType":["references"],"jpcoar:relatedTitle":[{"@value":"HPLC quantification of the dihydrochalcones, aspalathin and nothofagin in rooibos tea (Aspalathus linearis) as affected by processing"}]},{"@id":"https://cir.nii.ac.jp/crid/1362825895102681984","@type":"Article","relationType":["references"],"jpcoar:relatedTitle":[{"@value":"Characterization of Phenolic Compounds in Rooibos Tea"}]}],"dataSourceIdentifier":[{"@type":"JALC","@value":"oai:japanlinkcenter.org:2008286945"},{"@type":"IRDB","@value":"oai:irdb.nii.ac.jp:03420:0005500257"},{"@type":"NDL_SEARCH","@value":"oai:ndlsearch.ndl.go.jp:R000000004-I031273395"},{"@type":"CROSSREF","@value":"10.3136/nskkk.68.84"},{"@type":"CIA","@value":"130007991795"},{"@type":"KAKEN","@value":"PRODUCT-23231226"},{"@type":"OPENAIRE","@value":"doi_dedup___::3206558dea441f106ee42c72e64428c2"}]}