Mineral contents of three wild-grown edible mushrooms collected from forests of south eastern Nigeria: An evaluation of bioaccumulation potentials and dietary intake risks

Abstract

This study investigates the trace metal contents of three wide-grown Nigerian edible mushrooms and their bioaccumulation potentials. Samples of mushroom fruiting body (n = 45) of Pleurotus tuberregium, Auricularia auricular and Lentinus squarrosulus and their wooden substrates (n = 45), respectively, were collected from forest regions in south-eastern Nigeria. The concentrations of Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni and Pb using flame AAS after mineralization using acid. The concentrations varied from 6.23 to 47.63 for Mg; 2.59 to 771 for Ca; 1.27 to 79.46 for Mn; 1.08 to 161 for Fe and BDL to 93.39 for Zn (mg/kg, dry weight). The levels of the other metals were generally low and non-detectable in some instance with maximum concentrations (mg/kg) of 13.45 for Cr; 3.13 for Pb; 4.63 for K; 8.34 for Cu; 1.53 for Na; 5.72 for Cd and 4.56 mg/kg for Ni. The Co contents were <1 mg/kg. The mushrooms did not bioaccumulate the metals. Dietary intakes of the metals from a meal portion (210 g) of the three mushrooms, when consumed by an adult will be below the PTWI set for these elements. The toxic hazard quotient (THQ) values for all the metals were very low (THQ < 1) indicating that the consumption of the mushrooms poses no health risk.

Keywords

• Bioaccumulation
• Mineralization
• Mushroom fruiting body
• Nigeria
• Trace elements
• THQ