Finally, the hydroxyl radical scavenging activity was calculated
according to the following formula: hydroxyl radical scavenging
activity (%) = (A0 − A1 + A2)/A0 × 100, where A0 is the absorbance of
control group (water instead of JQPs), A1 is the absorbance of sample
in reactive system and A2 is the final absorbance of sample.