Mercury content of the cultivated mushroom Agaricus bisporus

Production of cultivated mushrooms continues to increase at a high rate. The chemical composition of mushrooms is, therefore, of both scientific and practical importance. The mercury content of Agaricus bisporus (variety K-23), the most important cultivated mushroom species worldwide was investigated. The caps and stalks of the fruiting bodies, originating from four independent cultivation cycles, were analyzed. Sample preparation was carried out by microwave digestion of dried mushroom material. Analysis was performed by hydride generation AAS. The average Hg contents of caps and stalks were found to be low (65 μg Hg/kg DM and 55 μg Hg/kg DM, respectively). Statistical analysis of the data did not indicate any significant differences in Hg content between the caps and stalk, or between the different flushes (production waves) of cultivation. The determined mercury concentrations are an order of magnitude lower than the average reported Hg-level of wild edible mushrooms. Our data confirming low Hg levels in A. bisporus is toxicologically reassuring, in view of the fact that certain wild Agaricus species (for example A. arvensis) are Hg accumulating.