Hydrolysis of proanthocyanidins polymer

The antioxidant activity of proanthocyanidins largely depends on the degree of polymerization.Proanthocyanidins polymer antioxidant activity is not as good as oligomer and the polymer is difficult to be absorbed by human body. Natural grape seeds Proanthocyanidins could be fully used through hydrolyzing the proanthocyanidins polymer into oligomer or monomer to have higher biological activity.Proanthocyanidins extracted from grape seeds were purified through AB -8 macroporous resin and gradient eluted with 33%,35%,37%,39%and 41%ethanol and hydrolyzed with H_2 SO_3.Hydrolysis effect was evaluated through average degree of polymerization,free radical scavenging rate and VC equivalent concentration.Hydrolysis mechanism and medium influence were discussed.The average degree of polymerization was reduced significantly and the antioxidant activity was improved.No byproduct was found in the hydrolysis product analyzed with spectrophotometry.The hydrolysis products were mainly OPC.