Effective extraction of oligomeric proanthocyanidin (OPC) from wild grape seeds

The Oligomeric proanthocyanidin (OPC) in green and black tea, grape seeds, grapes and wine has raised much attention but that OPC in wild grape seed remains to be intensively investigated. This study investigated the total OPC contents and total antioxidant activity of wild grape seeds and developed an efficient extraction process with various temperatures, solvent compositions and times. Also, a chromatography column packed with the Dia-ion HP-20 resin was used for further purification of the OPC. The total OPC contents were determined with the Folin-Ciocalteu reagent, and the antioxidant activity using total antioxidant potential (TAP) and 1,1-diphenyl-2picrylhydrazyl (DPPH). The yield of final purified OPC was 1.78 (+)-catechin equivalent (CE) g/100 g, with IC50 activities of TAP and DPPH of 31.60 and 15.70 mug/mL. These activities of the final purified OPC were about two times higher than that of the BHA used as a reference sample.