The trace element content of top-soil and wild edible mushroom samples collected in Tuscany, Italy

Abstract

The amount of the trace elements As, Ba, Cd, Cr, Cu, Hg, Li, Mn, Ni, Pb, Rb, Se, Sr, and Zn was measured in top soils and edible mushrooms, Boletus edulis, Macrolepiota procera, collected at five distinct green microhabitats inside the Lucca province, North-Central Italy (years 2008-2009). Results showed a top soil element content within the Italian statutory limits. Concerning the amount of mushroom elements, we observed significant species-differences obtaining higher levels of Ni, Rb, and Se in B. edulis or As, Pb, Cu in M. procera. Bioaccumulation factors (BCFs: element in mushroom/element in soil) resulted species-dependent and element-selective: in particular, B. edulis preferentially accumulated Se (BCFs varying from 14 to 153), while M. procera mainly concentrated Cu (BCFs varying from 5 to 15). As well, both species displayed between-site BCF differences. By a multivariate principal component approach, cluster analysis (CA), we could resolve two main clusters of soil element composition, corresponding to the most ecologically divergent sites. Besides, CA showed no cluster relating to element contents of B. edulis at the different collection sites, while a separation in groups was found for M. procera composition with respect to harvesting locations, suggesting uptake systems, in this saprotrophic species, sensitive to microhabitat. Regarding consumer safety, Cd, Hg, Pb levels resulted sometime relevant in present samples, never reaching values from current literature on mushrooms collected in urban-polluted areas. Our findings encourage a deeper assessment of the molecular mechanisms of metal intake by edible mushrooms, encompassing genetic biochemical and geo-ecological variables, with particular awareness to element bioavailability in soils and fungi.

Update on element content profiles in eleven wild edible mushrooms from family Boletaceae

“…The concentrations of this element obtained in study by [15] from Italy ranged between 62.5 and 311.0 mg/kg in B. edulis, which is very similar to our result for the same mushroom (57.83 mg/kg). Recommended daily intake varies between 1 and 5 mg.…”

“…The highest content of Cu was found in mushroom B. appendiculatus (our value is 34.25 mg/ kg) (18 mg/kg) [34] and the lowest in X. badius (our value is 4.66 mg/kg) (1.4-2.2 mg/kg) [23]. According to earlier data, copper contents of mushroom samples have been reported to be (11-77 mg/kg) [15], (51.99-85.76 mg/ kg) [2], (109 mg/kg in polluted area) [23] and (18.3 mg/ kg) [43], for B. edulis. Our value for L. pseudoscabrum (27.23 mg/kg) was similar to result recorded by [18], who analyzed different mushrooms and reported 19-48 mg/kg.…”

“…More than half of samples showed higher content of Zn than it is allowed. However, concentrations of Zn in the literature have been reported to be in the ranges: B. edulis, (43-35 mg/kg) [15] and (63.7-133.4 mg/kg) [2]; L. pseudoscabrum, (93-420 mg/kg) [18]; X. crysenteron (111.9-162.3 mg/kg) [2] and X. badius, (162.3-225.7 mg/ kg) [2]. Obtained zinc values are in agreement with the literature values.…”

Mineral Constituents of Edible Field Parasol (Macrolepiota procera) Mushrooms and the Underlying Substrate from Upland Regions of Poland: Bioconcentration Potential, Intake Benefits, and Toxicological Risk

“…For some of the sampled sites, Ag and Hg were highly bioconcentrated by M. procera and their BCF values reached more than 100. Earlier studies reported that M. procera has the ability to efficiently bioconcentrate Hg [54][55][56][57]. This species, apart from being rich in the essential elements (including Cu and Zn), is also rich in Cd, Pb, Hg, and Ag [2,14,26,40,56].…”

Cultivation of mushrooms for production of food biofortified with lithium

“…Its mean concentration reported for wild-growing mushrooms collected from different locations in Hungary and Italy amounted only to 0.19 and 0.25 mg kg −1 dry weight, respectively [18,19], while in cultivated Pleurotus mushrooms, Li content was found to be below detection limit [20]. Recently, however, the concept of mushrooms enriched in various elements such as selenium, zinc or copper for use as functional foods has been developed [21][22][23].…”