Improved stability of (+)-catechin and (-)-epicatechin by complexing with hydroxypropyl-beta-cyclodextrin: Effect of pH, temperature and configuration

卷:196

Liu, Min ; Zheng, Yan ; Wang, Chunmei ; Xie, Jimin ; Wang, Bingquan ; Wang, Zhengping ; Han, Jun ; Sun, Dezhi ; Niu, Meiju

Liaocheng Univ

关键词: (+)-Catechin;    (-)-Epicatechin;    Hydroxypropyl-beta-cyclodextrin;    Isothermal titration calorimetry;    Fluorescence spectroscopy;    Stability;   

DOI  :  10.1016/j.foodchem.2015.09.016

学科分类：食品科学和技术

【 摘 要 】

The stability and bioavailability of catechins, a kind of tea polyphenols with health benefit, could be improved by complexing with cyclodextrins. The aim of this study was to investigate the complexation of two geometrical isomers, (+)-catechin and (-)-epicatechin, with hydroxypropy1-beta-cyclodextrin (HP-beta-CD) in tris-HCI buffer solutions at pH 6.8-8.0 using isothermal titration calorimetry, fluorescence and proton nuclear magnetic resonance spectroscopy. Experimental results showed that these inclusion interactions are primarily enthalpy-driven processes. The complexation constant (K-C) of EC + HP-beta-CD complex was less than that of CA + HP-beta-CD at the same temperature and pH value. Temperature and pH studies showed that the IQ value decreased with the rise of temperature and pH. Stability study indicated that HP-beta-CD showed a stronger protection effect on CA than that on EC. The different inclusion modes between CA and EC were discussed in terms of the discrepancy in their molecular structures. (C) 2015 Elsevier Ltd. All rights reserved.