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

Agaricus bisporus'. Lentinula edodes, Pleltrotus ostreatus, Pleurotus eryngii and Grifola frondosa were analyzed for antioxidant capacity, its 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 mu mol of Trolox equivalents (TE)/g dry weight (dw). HORAC values ranged from 3.0 to 13.6 mu mol of caffeic acid equivalents/g dw. NORAC values ranged from 2.0 to 9.0 mu mol 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 me 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). (c) 2007 Elsevier Ltd. All rights reserved.