2008年1月
Effect of cyclodextrins on the thermal epimerization of tea catechins
Food Science and Technology Research
- ,
- ,
- ,
- 巻
- 14
- 号
- 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
- ID情報
-
- DOI : 10.3136/fstr.14.83
- ISSN : 1344-6606
- SCOPUS ID : 61849130033