Subcritical water extraction of Diosgenin from Dioscorea nipponica Makino and its antioxidant activity

Subcritical water extraction (SWE) was used as an alternative and environmentally friendly method for extraction of diosgenin from Dioscorea nipponica Makino (DNM). The effects of extraction temperature (75-175 degrees C) and time (15-45 min) on the diosgenin yield and antioxidant activity of extracts from DNM were analyzed. The profiles of extraction compounds at different temperatures were determined by HPLC. Results showed that diosgenin extraction was significantly (P < 0.05) affected by the extraction time and temperature and their interaction. The antioxidant activity was also affected by treatment time and temperature. The high antioxidant capacity was correlated with the high diosgenin content. Subcritical water may be a potential medium for diosgenin production.