MINERAL ELEMENTS OF WHITE, GREY, YELLOW AND PINK OYSTER MUSHROOMS (HIGHER BASIDIOMYCETES)

Abstract

Oyster mushroom has ecological importance in maintaining balance in the environment by recycling chemical elements between the soil, organisms and the atmosphere by industrial applications to produce highly protein foods when treat and clean up pollutants in same time. Minerals value (C, N, Co, Pb, Fe, Ni, Cu, Zn, Cd and Mn) of fruiting bodies of four oyster mushrooms species; Pleurotus ostreatus (grey), P. ostreatus (white), P. cornucopiae var. citrinopileatus (bright yellow) and P. salmoneostramineus (pink), were investigated on three mixtures; F1 (wheat straw alone 100%), F2 (wheat straw 70%, white sawdust 20% and Iraqi date palm fiber "fibrillum" 10% mixture) and F3 (wheat straw 50%, white sawdust 30% and fibrillum 20% mixture). The kinds of substrates showed significant (P<0.05) differences of mineral composition of mushroom that due to metal content of each substrate, whereas the mixture which composed from one substrate was poorer in mineral value compared with others which composed from more one. Generally, Fe, Ni and Cd have been increased in substrates, also increased in fruiting bodies of oyster mushroom. These mineral levels were below the safety limits defined by FAO/WHO for weekly Required Dietary Intake (RDI).