Comparative study on antioxidant activities of three sources of pomegranate polyphenols

Objective: To comparatively study the antioxidant activities of pomegranate polyphenols which were extracted from pomegranate peel, juice and residue respectively.Method: The antioxidant activities in vitro were measured by the methods of deoxidization capability, superoxide anion radical scavenging capacity, hydroxyl radical scavenging capacity, DPPH radical scavenging capacity and anti- lipid peroxidation capacity.Result: The order of deoxidization capabilities was: pomegranate residue polyphenols ( PRPs) > pomegranate peel polyphenols ( PPPs) > pomegranate juice polyphenols ( PJPs) .The order of superoxide anion radical scavenging capabilities was: PRPs > PJPs > PPPs.The order of hydroxyl radical scavenging capabilities was: PJPs > PRPs > PPPs.The order of DPPH radical scavenging capabilities was: PJPs > PRPs > PPPs.The order of anti- lipid peroxidation capabilities was: PRPs > PJPs > PPPs.Conclusion: Three kinds of pomegranate polyphenols had significant antioxidant and free radical scavenging activities, and their antioxidant activity sequences were different according to the evaluation system.In general, the antioxidant activities of PRPs and PJPs were higher than PPPs, this may be related to the polyphenol compositions.