a b s t r a c tAgaricus brasiliensis is a mushroom native from Brazil largely studied due to its polysaccharide contents, particularly b-glucans. In this study, the phenolics and organic acids contents as well as the antioxidant activities of its fruiting bodies and its mycelia obtained from submerged cultivation were compared. The hydroalcoholic extracts obtained from the fruiting bodies, early stationary mycelia and late stationary mycelia contain at least ten phenolic compounds and ten organic acids. Three phenolic compounds were identified as gallic acid, syringic acid and pyrogallol. Eight organic acids were identified as benzoic, oxalic, malic, acetic, alpha-ketoglutaric, citric, fumaric and trans-aconitic acids. All extracts presented antioxidant properties. The latter were evaluated by four assays: DPPH and ABTS radical scavenging activities, chelating ability for ferrous ions and inhibition of lipid peroxidation. The fruiting body extracts were more effective in the DPPH radical scavenging activity and lipid peroxidation inhibition that the mycelia extracts (P 0.05). The mycelia extracts were more effective in the ABTS radical scavenging activity and ferrous ion chelating ability (P 0.05). In conclusion, our results show that the mycelia of A. brasiliensis obtained in submerged cultivation can also be, as its fruiting bodies, valuable sources of antioxidant compounds.

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In this study, the antioxidant properties and the polyphenolic contents of raw and cooked pinhão seeds were evaluated. Four methods were used to evaluate the antioxidant activity: 1,1-diphenyl-2picrylhydrazyl free radical scavenging (DPPH), 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid scavenging (ABTS), ferrous ions chelating activity and lipid peroxidation inhibition (LPO). The EC 50 values (extract concentration producing 50% antioxidant effect), in μg/ml extract for raw and cooked extracts yielded respectively: DPPH, 870.7±30.8 and 112.6±5.4; ABTS, 170.7±7.8 and 52.1±2.1; ferrous ions chelating activity, 1,719±84.8 and 761±77.1; and LPO, 55.9±4.7 and 53.8±4.5. The improvement in the antioxidant activity in the cooked seeds can be attributed to the migration of polyphenolic compounds from coat to seed during cooking (5.92 ± 0.09 μg/mg and 24.06 ± 1.3 μg/mg in the raw and cooked seed extracts, respectively). Both raw and cooked seeds presented elevated amounts of catechin, 17.49±0.06 and 21.08±0.09 mg/100 g of seed, respectively.

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