Bioavailability of (-)-epicatechin upon intake of chocolate and cocoa in human volunteers.

We evaluated the levels of (-)-epicatechin (EC) and its metabolites in plasma and urine after intake of chocolate or cocoa by male volunteers. EC metabolites were analyzed by HPLC and LC/MS after glucuronidase and/or sulfatase treatment. The maximum levels of total EC metabolites in plasma were reached 2 hours after either chocolate or cocoa intake. Sulfate, glucuronide, and sulfoglucuronide (mixture of sulfate and glucuronide) conjugates of nonmethylated EC were the main metabolites present in plasma rather than methylated forms. Urinary excretion of total EC metabolites within 24 hours after chocolate or cocoa intake was 29.8+/-5.3%'; and 25.3+/-8.1% of total EC intake. EC in chocolate and cocoa was partly absorbed and was found to be present as a component of various conjugates in plasma, and these were rapidly excreted in urine.