In order to purify isoflavones by column chromatography from soybean whey,the discarded by-product in the production of soybean protein isolate,the adsorption and desorption characteristics of four kinds of macroporous resins for isoflavones were comparatively investigated.D4006 resin was chosen as the adsorbent.Before column chromatography, the soybean whey was ultrafiltrated and extracted with ethyl acetate to remove protein and other components.The sample containing isoflavones was passed through a column(30 mm×800 mm) packed with D4006 resin at the flow rate of 1 ml·min -1 at 25℃.The concentration of isoflavones in the sample was 1 mg·ml -1.The volume of the sample was 2.67 liters per liter resin.After adsorption, the resin was gradient-eluted by using aqueous ethanol solution (from 20% to 95% ethanol, by volume) at the flow rate of 1 ml·min -1 at 75℃.The eluate was vacuum-distilled to remove ethanol and water, and then was vacuum-dried to obtain a solid product.Under these conditions, a product with 72.5% of soybean isoflavones determined by HPLC was obtained.
