Preparation of culinary-medicinal maitake mushroom, Grifola frondosa (Dicks.: Fr.) S.F. Gray (Aphyllophoromycetideae)-fermented wheat and its antioxidant properties.

ABSTRACT

The optimization of solid-state fermentation conditions for mycelial growth in wheat by culinary-medicinal maitake mushroom, Grifola frondosa (Dicks. Fr.) S.F. Gray was studied. The results from the center of the design analysis showed that the recommended optimal conditions for carbon, nitrogen sources, and temperature were 19 mg lactose/g, 2.0 mg malt extract/g, and 30 degrees C, respectively. Under these conditions, the mycelial biomass of 533.1 mg/g was obtained in fermented wheat, comparable to that (545.7 mg/g) obtained using the one-factor-at-a-time method. Based on the results obtained, EC50 values of ethanolic and hot water extracts from fermented wheat were 1.13-15.27 mg/mL, indicating that fermented wheat was effective in antioxidant activity, reducing power, scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radicals, and chelating ability on ferrous ions. Total phenol contents of both extracts were 13.35 and 23.01 mg/g, respectively. Accordingly, the information obtained would be applicable for the cultivation and consumption of G. frondosa-fermented wheat to provide its beneficial health effects.