2.2. Preparation of ethanolic extract of A. bisporus
For ethanolic extraction, 2 g of A. bisporus powder was extracted by stirring with
100 ml of 80% ethanol at 25 C for 24 h under dark condition. After centrifugation at
5000g for 10 min, the residue was re-extracted twice with 80% ethanol as described
above. The supernatants were pooled together, concentrated under reduced pressure
at 40 C and lyophilized. The dried extract thus obtained was used directly
or redissolved in ethanol or physiological saline for the determination of antioxidant
activity and analysis of the phenolic components.