An integrated antioxidant activity fingerprint for commercial teas based on their capacities to scavenge reactive oxygen species

•A novel on-line HPLC-DAD-CL developed to screen for OH scavengers in commercial tea.•An integrated antioxidant activity fingerprint for commercial tea was developed.•To comprehensively evaluate the quality of 12 batches of commercial tea.•Comparing the total H2O2-, O2−-, and OH-scavenging capacities in commercial tea.

An integrated antioxidant activity fingerprint, based on on-line screening methods for three reactive oxygen species (ROS: superoxide anion radical, hydrogen peroxide, and hydroxyl radical) was developed to comprehensively evaluate the quality of 12 batches of commercial tea. High-performance liquid chromatography (HPLC) coupled with a chemiluminescent detector was used to determine the antioxidant characteristics of a selection of teas as bioactivity fingerprints. An HPLC-electrospray ionization-mass spectrometry analysis was used to determine the chemical profiles of the teas in the chromatographic fingerprints. All of the green teas (S01-S08) were better scavengers of the three ROS compared to the oolong teas (S09-S12). The main scavengers of the three ROS in green tea were 5-galloylquinic acid, (−)-epigallocatechin-3-O-gallate, and (−)-epicatechin-3-O-gallate, whereas in oolong tea, they were (−)-epigallocatechin-3-O-gallate and (−)-epigallocatechin. This study demonstrates that comprehensive fingerprinting is a potentially meaningful method for evaluating the quality of food products.