Free phenolic acids in human urine after drinking coffee rich in chlorogenic acids

The pharmacokinetics study of free urinary excretion of phenolic acids in human volunteers (with and without a colon) who drank instant coffee was successfully conducted. The objective of the study was to identify the possible degradation products of coffee hydroxycinnamates in vivo. All volunteers displayed a substantial increase in excretion of free 3-(3-hydroxyphenyl)-3-hydroxypropionic acid, dihydroferulic acid, ferulic acid and 3-hydroxyhippuric acid within 8 – 24 h after drinking coffee. In total, mean concentration of urinary free phenolic acids excreted was 134 ± 43 μmole, which was equivalent to 29.4% of chlorogenic acid intake and significantly higher (p 0.05) than phenolic acids excreted when only water was consumed. The presence of free phenolic acids in urine after drinking coffee indicated that coffee maybe able to provide health benefits to humans. This is because free phenolic acids have higher antioxidant activities in comparison to conjugated phenolic acids