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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- 作者：Karen A. Cooper ; Esther Campos-Gimé ; nez ; Diego Jimé ; nez Alvarez ; Korné ; l Nagy ; Jennifer L. Donovan ; Gary Williamson
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2007
- 出版时间：April 18, 2007
- 年：2007
- 卷：55
- 期：8
- 页码：2841 - 2847
- 全文大小：139K
- 年卷期：v.55,no.8(April 18, 2007)
- ISSN：1520-5118
文摘
Chocolate and other cocoa-containing products are a rich source of polyphenols. This paper describesan ultra-performance liquid chromatography (UPLC) method that can separate and quantify in 3 minsix of the major chocolate polyphenols: catechin; epicatechin; B2 (epicatechin-4
-8-epicatechin);B5 (epicatechin-4-6-epicatechin); C1 (epicatechin-4-8-epicatechin-4-8-epicatechin); and tetramerD (epicatechin-4-8-epicatechin-4-8-epicatechin-4-8-epicatechin). A survey of 68 chocolate samplesindicated that there was a strongly predictive relationship between epicatechin and the other individualpolyphenols, especially procyanidin B2 (R 2 = 0.989), even though the chocolates came from variedsources and manufacturers. The relationship was less strong with catechin, and so further work toexplore the reasons for this difference was performed. Chiral analysis on a subset of 23 chocolatesshowed that (-)-epicatechin had a predictive relationship with (+)-catechin in line with the otherpolyphenols, but not with (-)-catechin (the predominant form). This indicates that (-)-catechin is themost affected by manufacturing conditions, possibly formed through epimerization from (-)-epicatechinduring processing. The results show that epicatechin concentrations can be used to predict the contentof other polyphenols, especially B2 and C1, and total polyphenols content. Finally, the (-)-catechincontent is not predictable from the epicatechin content, and it is concluded that this is the main formof polyphenol that varies according to manufacturing conditions and cocoa origin.
-8-epicatechin);B5 (epicatechin-4-6-epicatechin); C1 (epicatechin-4-8-epicatechin-4-8-epicatechin); and tetramerD (epicatechin-4-8-epicatechin-4-8-epicatechin-4-8-epicatechin). A survey of 68 chocolate samplesindicated that there was a strongly predictive relationship between epicatechin and the other individualpolyphenols, especially procyanidin B2 (R 2 = 0.989), even though the chocolates came from variedsources and manufacturers. The relationship was less strong with catechin, and so further work toexplore the reasons for this difference was performed. Chiral analysis on a subset of 23 chocolatesshowed that (-)-epicatechin had a predictive relationship with (+)-catechin in line with the otherpolyphenols, but not with (-)-catechin (the predominant form). This indicates that (-)-catechin is themost affected by manufacturing conditions, possibly formed through epimerization from (-)-epicatechinduring processing. The results show that epicatechin concentrations can be used to predict the contentof other polyphenols, especially B2 and C1, and total polyphenols content. Finally, the (-)-catechincontent is not predictable from the epicatechin content, and it is concluded that this is the main formof polyphenol that varies according to manufacturing conditions and cocoa origin.