Five kinds of ear mushrooms are commercially available in Taiwan, including black, red, jin, snow, and silver ears. Methanolic extracts were prepared from these ear mushrooms, and their antioxidant properties were studied. For all methanolic extracts from ear mushrooms, the antioxidant activities in the 1,3-diethyl-2-thiobarbituric acid method were moderate (38.6 approximately 74.6%) at 1.0-5.0 mg/mL. Methanolic extracts from red, jin, and snow ears 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 the descending order of snow > black approximately red approximately jin > silver ears. The scavenging effect of methanolic extracts from ear mushrooms on 1,1-diphenyl-2-picrylhydrazyl radicals was excellent except for that from silver ears. Ear mushroom extracts were not good scavengers for hydroxyl free radicals but were good chelators for ferrous ions. Naturally occurring antioxidants, including ascorbic acid, tocopherols, and total phenols, were found in the methanolic extracts. However, beta-carotene was not detected. Total antioxidant components were 15.69, 30.09, 27.83, 49.17, and 31.70 mg/g for black, red, jin, snow, and silver ears, respectively.

Grifola frondosa is an edible mushroom currently available in Taiwan. Ethanolic, cold-water and hot-water extracts were prepared and their antioxidant properties were investigated. At 1 mg/mL, G. frondosa T1 and T2 cold-water extracts showed high reducing powers of 1.02 and 0.50, respectively. Chelating abilities on ferrous ions of G. frondosa T1 and T2 were higher for cold-water extracts than for ethanolic and hot-water extracts. For the scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, G. frondosa T1 and T2 extracts were effective in the following order: ethanolic > hot-water > cold-water. The G. frondosa hot-water extract showed high scavenging ability on superoxide anions. Total phenols, flavonoids, ascorbic acid and α-tocopherol are the major antioxidant components found in the various G. frondosa extracts. Based on EC50 values (<20 mg/mL) obtained, the various extracts from G. frondosa investigated in this study display potent antioxidative properties.

Five kinds of ear mushrooms are commercially available in Taiwan, including black, red, jin, snow, and silver ears. Ash contents ranged from 2.05 to 6.14% of dry weight. Carbohydrate contents ranged from 68.88 to 88.14%. The jin and snow ears contained high amounts of crude fat (4.48 and 4.54%, respectively). The jin and snow ears also contained high amounts of crude fiber (11.69 and 8.51%, respectively). Crude protein contents were high in the black and snow ears (15.46 and 12.53%, respectively). Ear mushrooms contained very low amounts of soluble sugars but high amounts of other reducing sugars. Total free amino acid contents ranged from 0.53 to 1.24 mg/g. Monosodium glutamate-like component contents ranged from 0.05 to 0.34 mg/g. Sweet component contents ranged from 0.17 to 0.50 mg/g. Bitter component content was high in the silver ear. Total 5‘-nucleotides contents ranged from 0.69 to 5.39 mg/g. Flavor 5‘-nucleotide contents were high in the snow and jin ears. In this study, the five kinds were considerably different in both their proximate compositions and taste components. Keywords: Ear mushrooms; Auricularia fuscosuccinea; Auricularia mesenteria; Auricularia polytricha; Tremella fuciformis; soluble sugars; free amino acids; 5‘-nucleotides