Ito H., Gonthier M.P., Manach C., Morand C., Mennen L., Remesy C., Scalbert A. (2005) Polyphenol levels in human urine after intake of six different polyphenol-rich beverages. Br J Nutr 94:500-9 PubMed (16197573)

Compound Mean content
Malvidin 3-O-glucoside 14.7 mg/g dry weight
Gallic acid 0.7 mg/g dry weight
Caffeic acid 0.04 mg/g dry weight
p-Coumaric acid 0.02 mg/g dry weight
Quercetin 0.08 mg/g dry weight
(+)-Catechin 0.04 mg/g dry weight