The effect of selenium on phenolics and flavonoids in selected edible white rot fungi

From the paper

Abstract

The objective of the study was to determine total phenolic and flavonoid content and composition as well as antioxidant activity in Pholiota nameko, Pleurotus eryngii and Pleurotus ostreatus growing on substrates supplemented with selenium salts. The concentration of Se in control samples (without Se addition) was 4.86 ± 0.12 mg/kg for P. nameko, 2.54 ± 0.22 mg/kg DW for P. ostreatus, and 7.34 ± 0.17 mg/kg DW for P. eryngii. The addition of selenium salts to the substrate resulted in increases of Se concentration in the fruiting bodies. Total phenolic and flavonoid concentration was the highest for P. nameko. In all examined mushrooms p-hydroxybenzoic, p-coumaric and ferulic acids and myricetin were identified, while gallic and t-cinnamic acids were identified only in P. nameko. The greatest inhibition of DPPH and ABTS radicals was confirmed for P. nameko, and the lowest for P. eryngii. Se supplementation at the concentration between 0.5 and 5.0 mmol/L inhibited growth of fruiting bodies of the mushrooms and enhanced the biosynthesis of phenolics and flavonoids. The increase of scavenging activity for all mushrooms was confirmed in Se-treated mushrooms. The inhibition of DPPH and ABTS radicals was correlated with total phenolic and flavonoid contents only for P. ostreatus.