Quantification of polyphenols and ergothioneine in cultivated mushrooms and correlation to total antioxidant capacity

Abstract Agaricus bisporus , Lentinula edodes , Pleurotus ostreatus , Pleurotus eryngii and Grifola frondosa were analyzed for antioxidant capacity, as measured by oxygen radical absorbance capacity (lipophilic and hydrophilic) (ORAC total ), hydroxyl radical averting capacity (HORAC), peroxynitrite radical averting capacity (NORAC), superoxide radical averting capacity (SORAC) assays, Folin-Ciocalteu reagent and ergothioneine (ERG) content. ORAC total values ranged from 39 to 138 μmol of Trolox equivalents (TE)/g dry weight (dw). HORAC values ranged from 3.0 to 13.6 μmol of caffeic acid equivalents/g dw. NORAC values ranged from 2.0 to 9.0 μmol TE/g dw. SORAC values ranged from 0.37 to 2.6 kunit superoxide dismutate equivalents/g dw. Polyphenols ranged from 4.2 to 10.6 mg gallic acid equivalents/g dw. A. bisporus mushrooms, especially portabellas, had higher antioxidant capacity relative to the specialty mushrooms tested. ERG ranged from 0.21–2.6 mg/g dw with L. edodes , P. ostreatus , G. frondosa containing a statistically significant greater amount compared to A. bisporus . A good correlation was found between ORAC total and polyphenols ( R 2  = 0.86).