Metal content and crude polysaccharide characterization of selected mushrooms growing in Romania

Three selected mushrooms growing in Romania, i.e. Armillaria mellea (Vahl.: Fr.) P.Kumm., Boletus edulis Bull. and Cantharellus cibarius Fr., were analyzed in terms of metal (measured in fruiting bodies) and crude polysaccharide content. Inductively coupled plasma mass spectrometry (ICP-MS) technique was used to determine the metal contents, revealing the abundant presence of several microelements such as copper (varied from 15.8 mg/kg in A. mellea to 64.1 mg/kg in C. cibarius), iron (varied from 118 mg/kg in B. edulis to 221 mg/kg in A. mellea) and zinc (varied from 77.3 mg/kg in A. mellea to 188 mg/kg in C. cibarius). Selenium content varied from 0.2 mg/kg in C. cibarius to 4.18 mg/kg in B. edulis. The yield of the crude polysaccharides content in mushrooms varied from 3.6% in Boletus edulis, to almost 7% in Armillaria mellea and their characterization was employed by Nuclear Magnetic Resonance and Infra-Red Spectroscopy, Gel Permeation Chromatography and Thermogravimetric Analysis. The antioxidant activity of the detected polysaccharides was evaluated by means of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging and ferrous ion chelating assays. The best DPPH radical scavenging activity was found in the crude polysaccharides extracted from A. mellea (CE50 = 222 ± 3 μg/mL).