Analyses of polyphenols in cacao liquor, cocoa, and chocolate by normal-phase and reversed-phase HPLC

The antioxidant polyphenols in cacao liquor, a major ingredient of chocolat e and cocoa, have been characterized as flavan-3-ols and proanthocyanidin o ligomers. In this study, various cacao products were analyzed by normal-pha se HPLC, and the profiles and quantities of the polyphenols present, groupe d by molecular size (monomers similar to oligomers), were compared. Individ ual cacao polyphenols, flavan3-ols (catechin and epicatechin), and dimeric (procyanidin B2), trimeric (procyanidin C1), and tetrameric (cinnamtannin A 2) proanthocyanidins, and galactopyranosyl-ent-(-)-epicatechin (2 alpha->7, 4 alpha->8)-(-)-epicatechin (Gal-EC-EC), were analyzed by reversed-phase H PLC and/or HPLC/MS. The profile of monomers (catechins) and proanthocyanidi n in dark chocolate was similar to that of cacao liquor, while the ratio of favan-3-ols to the total amount of monomeric and oligomeric polyphenols in the case of pure cocoa powder was higher than that in the case of cacao li quor or chocolate.