Elemental Distribution in Selected Agaricus and Rhizina Mushrooms in South Africa

The levels of calcium, magnesium, iron, manganese, lead, chromium and cadmium in four prevalent mushroom species in South Africa, namely two edible Agaricus bisporus species, one inedible Agaricus xanthodermus species and a poisonous type mushroom, Rezhina undulata are reported. Analytical results from the open vessel and microwave digestion approaches were compared. While higher levels of Ca and Mg were found in the edible types, the inedible and poisonous type mushrooms had relatively high levels of manganese, chromium, cadmium and lead. Agaricus xanthodermus had Ca (204), Mg (660), Fe (306), Mn (30), Cr (16.2), Pb (50.6) and Cd (29.5) mg kg⁻¹ by dry weight, while Rhizina undulata, which grows on dead wood recorded Ca (121), Mg (517), Fe (130), Mn (30.7), Cr (32.1), Pb (49.5) and Cd (20) mg kg⁻¹ by dry weight.

Key Words:

• Mushrooms
• Edible
• Poisonous
• Elemental distribution
• Agaricus spp.
• Rhizina undulata.

ACKNOWLEDGEMENTS

Authors thank the National Research Foundation, Pretoria and the University of KwaZulu-Natal for funding. Authors also thank Prof. A. Kindness, UKZN- School of Chemistry for his help in sample preparation and the staff of Botany department for positively identifying the investigated mushroom species.

Notes

*Mean values of triplicate runs from the same samples.

*Mean values from triplicate experiments.

*Mean values from triplicate experiments.