Oyster mushroom (Pleurotus ostreatus) belongs to the best known wood-destroying fungi. In the nature it grows on trunks and stumps of deciduous trees but nowadays it is also cultivated on modified lignocellulose substrates in oyster mushroom farms. It possesses a very pleasant flavour and piquant taste.
As most fungi it contains up to 90% water, but owing to its protein and amino acids content, low fat content, content of 9-group vitamins and a wide spectrum of mineral substances it represents a good source of biologically valuable substances for human nutrition. The saccharidic complex of oyster mushroom is characterized by low content of digestible carbohydrates and by a relatively high content of polysaccharides which take part in formation of edible fibre. In the past mushrooms were generally regarded as less valuable foodstuffs especially for their low energetic value and high fibre content. With respect to the present knowledge their importance is coming to the foreground [I].
Although some authors report that the mineral composition of oyster mushroom is biologically highly valuable -because of its content of macroelements, but especially because of numerous microelements that began to be appreciated only recently -relatively few data are available (2-101. This paper will contribute to enhancing information in this field.