Chemiluminescence determination of free radical scavenging abilities of ‘tea pigments’ and comparison with ‘tea polyphenols’

The objectives of this paper were to determine the free radical scavenging abilities of ‘tea pigments’ towards superoxide radical anion (O2−) and hydroxyl radical (OH), and to make a comparison with ‘tea polyphenols’ using a chemiluminescence technique. O2− and OH were generated from pyrogallol autoxidation and Fenton-type reaction, respectively. ‘Tea pigments’ could scavenge O2− and OH at EC50 values of 0.08 and 0.003 mg/ml, respectively, and the kinetics of the scavenging reactions varied with the concentration, suggesting the operation of different mechanisms. In addition, the free radical scavenging abilities and kinetics of ‘tea pigments’ were similar to those of ‘tea polyphenols’.