Extraction, purification and antioxidation of proanthocyanidins of Elaeagnus angustifolia L. Jujubes

The extraction of proanthocyandins from Elaeagnus angustifolia L. jujubes was studied. The optimum conditions of extraction are as follows: the rate of solvent to material is 9∶1, the extraction temperature is 76℃, extraction time is 86 min for three times, the concentration of ethanol is 72％, pH value is 5.0. And the extraction yield is 95.9%. The proanthocyandins was purified by solid-phase extraction. The results show that the purity of proanthocyandins of Elaeagnus angustifolia L. jujubes is 89.91％; the yield of proanthocyandins is 4.23%. The antioxidant ability of proanthocyandins was studied too. And the results show that proanthocyandins has better antioxidant ability comparing with some other antioxidants.