EVALUATION OF HEAVY METALS CONTENT IN EDIBLE MUSHROOMS BY MICROWAVE DIGESTION AND FLAME ATOMIC ABSORPTION SPECTROMETRY

Abstract

The aim of this work was to determine the heavy metal (Cd, Cr, Ni, Pb, Mn, Zn, Fe and Cu) content of the fruiting bodies (cap and stipe) of four species (Amanita caesarea, Pleurotus ostreatus, Fistulina hepatica and Armillariella mellea) and their substrate, collected from forest sites in Dâmboviţa County, Romania. The elements were determined by Flame Atomic Absorption Spectrometry (FAAS) after microwave assisted digestion. From the same collecting point were taken n = 5 samples of young and mature fruiting bodies of mushrooms and their substrate. The high concentrations of lead, chrome and cadmium (Pb: 0.25 – 1.89 mg.kg-1, Cr: 0.36 – 1.94 mg.kg-1, Cd: 0.23 – 1.13 mg.kg-1) for all collected wild edible mushrooms, were determined. These data were compared with maximum level for certain contaminants in foodstuffs established by the commission of the European Committees (EC No 466/2001). A quantitative evaluation of the relationship of element uptake by mushrooms from substrate was made by calculating the accumulation coefficient (Ka). The moderately acid pH value of soil influenced the accumulation of Zn and Cd inside of the studied species. The variation of heavy metals content between edible mushrooms species is dependent upon the ability of the species to extract elements from the substrate and on the selective uptake and deposition of metals in tissue.

Keywords

• accumulation coefficient
• FAAS
• heavy metal
• microwave digestion
• mushroom