Urpi-Sarda M., Monagas M., Khan N., Lamuela-Raventos R.M., Santos-Buelga C., Sacanella E., Castell M., Permanyer J., Andres-Lacueva C. (2009) Epicatechin, procyanidins, and phenolic microbial metabolites after cocoa intake in humans and rats. Anal Bioanal Chem 394:1545-56 PubMed (19333587)

Compound Mean content
(-)-Epicatechin 0.34 mg/g
(+)-Catechin 0.1 mg/g
Procyanidin dimer B2 0.23 mg/g
Quercetin 3-O-glucoside 0.02 µg/g
Quercetin 0.01 µg/g
Polyphenols, total 1.08 mg/g