The effect of green tea powder extracts (GTPEs) on antioxidant activity is showed in Table 5. The scavenging rate of GTPEs on $OH had statistical differences (P < 0.05) between CK and other treatments, but no significant differences (P > 0.05) among GTP20 to GTP120. Although the scavenging capacity of GTPs on O2 . rose with the particle size increasing during superfine grinding, the differences were not statistically significant