The Effects of Subcritical Water Treatment on Antioxidant Activity of Golden Oyster Mushroom

Subcritical water (SCW) extraction of golden oyster mushroom (GOM) was carried out at various temperatures (50, 100, 150, 200, 250, and 300 °C) for 10, 30, and 60 min, and the antioxidant and certain physiological activities of the extracts were evaluated. SCW treatment of GOM increased the antioxidant activity of the extracts. The SCW extraction of GOM at 250 °C for 60 min or 300 °C for 30 min showed relatively high levels of total phenolic content, 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, and reducing power. The β-glucan content was the highest when SCW extraction was carried at 200 °C for 60 min, while the highest 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging activity occurred at 300 °C for 60 min. These results indicate that the temperature and time of SCW extraction significantly affect the antioxidant activity as well as the nutraceutical compound levels of GOM extracts.