Optimal method to extract total isoflavones from red clover by subcritical water

The extraction process of extracting total isoflavones from red clove was optimized by using subcritical water method in this study. The extraction temperature, ratio of liquid to material, extraction time and extraction pressure were tested by a single factor anlysis and orthogonal experiment design. This study showed that the optimal conditions were that the extraction temperature was 120 ℃, extraction time was 15 min, ratio of liquid to material was 40 mLg-1 and extraction pressure was 1.4 MPa.The extracting rate of the total isoflavones from the red clove was 33.61 mgg-1.