Studies on antioxidant activities of apple polyphenol extracts in vitro

The antioxidant activities of apple polyphenol extracts were studied and evaluated in vitro by determining the reducing capacity, antioxidant activity on lipid-peroxidation, and scavenging effects on active oxygen radicals generated by various system. The results showed that apple polyphenol extracts had stronger reducing capacity, antioxidant activity on lipid-peroxidation, and scavenging effects on hydroxyl radical and superoxide anion radical than ascorbic acid at the same concentration. In the range of test concentration, the maximum scavenging or inhibition rate of apple polyphenol extracts to linoleic acid auto-oxidation, hydroxyl radical generated by Fenton reaction, superoxide anion radical generated by illuminating riboflavin and pyrogallol auto-oxidation system was 94.4%, 96.64%, 95.19% and 90.48% respectively. The results suggested that the apple polyphenol extracts was an excellent natural antioxidant and free radicals scavenger.