Abstract
inhibitory effect of 70% acetone extract of enokitake mushroom Flammulina velutipes on the mealnosis of shrimp Trachypenaeus curvirostris was investigated. The acetone extract effectively prevented the mushroom tyrosinase activity as well as melanosis of American crayfish Procambarus clarkii hemolymph. When each of two fractions of the acetone extract, which were unadsorbed on both of Dowex 50W X8 and/or DEAE-TOYOPERAL 650 columns, was mixed with hemolymph of the American crayfish, the melanosis that usually occurs in the heparinized hemolymph was effectively prevented. Immersing shrimp in the acetone extract of enokitake mushroom delayed the color darkening usually found in the post-mortem shrimp. These observations suggested that enokitake mushroom contained certain compounds that inhibit the formation of melanin due to the catalytic oxidation of polyphenol oxidase, as well as mushroom tyrosinase activity.
