| abstract |
A material containing proanthocyanidine, which is rich in OPC having a high physiological activity, can be obtained by extracting proanthocyanidine from a plant, then bringing the obtained extract into contact with a definite amount of chitin, chitosan or a derivative thereof and recovering the unadsorbed matters. By further treating this proanthocyanidine-containing material with a synthetic resin adsorbent, a proanthocyanidine-containing material with an extremely high OPC content can be obtained. |