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.