Selenium contents of Portuguese commercial and wild edible mushrooms

The selenium contents of 66 mushroom samples, wild growing or commercially available in Portugal, fresh, canned or dried, were determined. The samples consisted of 18 mushroom species, mainly selected in accordance with their availability and consumer preference. The selenium contents varied considerably between different mushroom species. The highest selenium contents were found in the wild species Boletus aestivalis (48.5 mg/kg dry weight, DW), Boletus pinophilus (19.9 mg/kg DW), Boletus edulis (14.9 mg/kg DW), Boletus aereus (12.3 mg/kg DW), Boletus fragans and Boletus spretus (∼2 mg/kg DW). Other mushrooms having considerable selenium contents included Marasmius oreades (1.5 mg/kg DW), Agaricus bisporus “Portobello” (1.25 mg/kg DW), A. bisporus (1.0 mg/kg DW) and Russula cyanoxantha (0.72 mg/kg DW). The selenium contents of these mushrooms are sufficient to provide nutritionally significant amounts in relation to the total daily intake of selenium. Other edible mushrooms, such as Lentinula edodes, Pleurotus ostreatus, Cantharellus cibarius,Craterellus cornucopioides and Lepista nuda, contained only small amounts of selenium. The importance of these mushrooms as a source of selenium is therefore marginal.