Rapid reversed phase ultra-performance liquid chromatography analysis of the major cocoa polyphenols and inter-relationships of their concentrations in chocolate
Rapid reversed phase ultra-performance liquid chromatography analysis of the major cocoa polyphenols and inter-relationships of their concentrations in chocolate
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DOI：
10.1021/jf063277c
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发表时间：
2007-04-18
影响因子：
6.1
通讯作者：
Williamson, Gary
中科院分区：
文献类型：
--
作者：
Cooper, Karen A.;Campos-Gimenez, Esther;Williamson, Gary
巧克力和其他含可可的产品是多酚的丰富来源。本文介绍了一种超高效液相色谱（UPLC）方法，该方法可以在3分钟内分离和定量巧克力中的六种主要多酚：儿茶素；表儿茶素;B2（表儿茶素-4 -8-表儿茶素）；B5（表儿茶素-4 -6-表儿茶素）；C1（表儿茶素-4 β -8-表儿茶素-4 β -8-表儿茶素）；四聚体D（表儿茶素-4 -8-表儿茶素-4 -8-表儿茶素-4 - β -8-表儿茶素）。一项对68个巧克力样本的调查表明，表儿茶素和其他多酚之间存在很强的预测关系，尤其是原花青素B2 (R(2) = 0.989)，即使巧克力来自不同的来源和制造商。这种关系与儿茶素的关系较弱，因此进一步的工作是探索这种差异的原因。对23块巧克力的手性分析表明，(-)-表儿茶素与(+)-儿茶素与其他多酚具有预测关系，但与(-)-儿茶素（主要形式）没有预测关系。这表明(-)-儿茶素受制造条件的影响最大，可能是在加工过程中由(-)-表儿茶素外显异构化形成的。结果表明，表儿茶素的浓度可以预测其他多酚的含量，尤其是B2和C1，以及总多酚的含量。最后，(-)-儿茶素含量不能从表儿茶素含量中预测出来，这是多酚的主要形式，根据制造条件和可可产地的不同而不同。
Chocolate and other cocoa-containing products are a rich source of polyphenols. This paper describes an ultra-performance liquid chromatography (UPLC) method that can separate and quantify in 3 min six of the major chocolate polyphenols: catechin; epicatechin; B2 (epicatechin-4 beta-8-epicatechin); B5 (epicatechin-4 beta-6-epicatechin); C1 (epicatechin-4 beta-8-epicatechin-4 beta-8-epicatechin); and tetramer D (epicatechin-4 beta-8-epicatechin-4 beta-8-epicatechin-4 beta-8-epicatechin). A survey of 68 chocolate samples indicated that there was a strongly predictive relationship between epicatechin and the other individual polyphenols, especially procyanidin B2 (R (2) = 0.989), even though the chocolates came from varied sources and manufacturers. The relationship was less strong with catechin, and so further work to explore the reasons for this difference was performed. Chiral analysis on a subset of 23 chocolates showed that (-)-epicatechin had a predictive relationship with (+)-catechin in line with the other polyphenols, but not with (-)-catechin (the predominant form). This indicates that (-)-catechin is the most affected by manufacturing conditions, possibly formed through epimerization from (-)-epicatechin during processing. The results show that epicatechin concentrations can be used to predict the content of other polyphenols, especially B2 and C1, and total polyphenols content. Finally, the (-)-catechin content is not predictable from the epicatechin content, and it is concluded that this is the main form of polyphenol that varies according to manufacturing conditions and cocoa origin.