Antioxidant properties of methanolic extracts from several ear mushrooms

Five kinds of ear mushrooms are commercially available in Taiwan, including black, red, jin, snows and silver ears. Methanolic extracts were prepared from these ear mushrooms, and their antioxidant properties were studied. Fo r all methanolic extracts from ear mushrooms, the antioxidant activities in the 1,3-diethyl-2-thiobarbituric acid method were moderate: (38.6 similar to 74.6%) at 1.0-5.0 mg/mL. Methanolic extracts from red, jin, and snow ear s showed excellent antioxidant activities in the conjugated diene method at 5.0 mg/mL. At 5.0 mg/mL, reducing powers of methanolic extracts were in th e descending order of snow > black approximate to red approximate to jin > silver ears. The scavenging effect of methanolic extracts from ear mushroom s on 1,1-diphenyl-2-picrylhydrazyl radicals was excellent except for that f rom silver ears. Ear mushroom extracts were not good scavengers for hydroxy l free radicals but were good chelators for ferrous ions. Naturally occurri ng antioxidants, including ascorbic acid, tocopherols, and total phenols, w ere found in the methanolic extracts. However, beta -carotene was not detec ted. Total antioxidant components were 15.69, 30.09, 27.83, 49.17, and 31.7 0 mg/g for black, red, jin, snow, and silver ears, respectively.