ANTIOXIDANT ACTIVITY OF EDIBLE MUSHROOMS Agaricus blazei (MURRILL) GROWN WITH DIFFERENT SUPPLEMENTS

The fungus Agaricus blazei (Murrill), known as “sun mushroom” is a Brazilian mushroom that has recently become attractive due to its antioxidant compounds, such as phenolic compounds, tocopherols, ascorbic acid, carotenoids and tannins. However, the presence and amount of these compounds can be different depending on the type of production and the supplement used in the substrate. Therefore, the aim of this study was to determine the antioxidant activity and the total phenolic content of tree different strains of the mushroom A. blazei [originated from Japan (JP), Brazil (ABZ) and Belgium (T2), respectively)] grown with four different handmade supplements (with and without formaldehyde addition), and two commercial ones. The antioxidant activity of hydro alcoholic extract (EtOH:H2O 80:20 v/v) was evaluated by the scavenging ability against 1,1-diphenyl-2-picryhydrazyl radical (DPPH•), ferric-reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) assays, while the phenolic content was evaluated by Folin-Ciocalteu method. The results were expressed as equivalent of gallic acid. The control ABZ, T2 and JP strains, cultivated without any supplement, showed high content of phenolic compounds with 73.85 ± 0.60, 57.29 ± 2.40 and 52.63 ± 0.60 mg EAG/100g, respectively. All supplemented samples were analyzed and, for the ABZ strain, the best result was obtained with a mix of supplements, while for the T2 strain, the commercial supplement, and the JP strain reached the best values with the addition of the supplement formulated with noble grains, obtaining 90.61 ± 0.90, 80.64 ± 0.60 and 85,31 ± 2,51 mg EAG/100g, respectively. Additionally, the higher DPPH• antioxidant activity was obtained for T2 strain supplemented with acerola juice waste (55.89 ± 2,06 mg EAG/100g), while for the FRAP method, the ABZ strain supplemented with the commercial compound presented more potent activity (242,86 ± 37.40 mg EAG/100g)), and, for the ORAC method, ABZ strain presented the higher antioxidant activity supplemented using the commercial compound in their cultivation (5,95 ± 0,58 g EAG/100g). Therefore, the present research confirms that the development of Agaricus blazei phenolic and antioxidant compounds is influenced by the strains and the supplement utilized.