論文

査読有り
2008年1月

Effect of cyclodextrins on the thermal epimerization of tea catechins

Food Science and Technology Research
  • Hisako Okumura
  • ,
  • Masaki Ichitani
  • ,
  • Takanobu Takihara
  • ,
  • Ko-Ki Kunimoto

14
1
開始ページ
83
終了ページ
88
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.3136/fstr.14.83

The epimerization reaction of tea catechins was investigated at pH 5.5 and 120°C in the absence/presence of cyclodextrins (CDs). In the absence of CDs, a considerable quantity (∼20%) of products originating from reactions other than the epimerization ("other products") was formed during the epimerization of gallated catechins. In the case of (-)-EGCg, addition of β-CD to the reaction solution reduced the quantity of these other products to just a few percent, but other CDs with different cavity sizes had little effect. Generally, the addition of β-CD increased the ratio of non-epi type catechins, that is, [non-epi type catechin] / ([epi type catechin]+[non-epi type catechin]). Molecular orbital (MO) calculations using the PM3 method suggested that non-epi type catechins are more thermodynamically stable than their epi-type counterparts, moving the equilibrium position in favor of non-epi type catechins in the epimerization process.

リンク情報
DOI
https://doi.org/10.3136/fstr.14.83
ID情報
  • DOI : 10.3136/fstr.14.83
  • ISSN : 1344-6606
  • SCOPUS ID : 61849130033

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