Postemsky Pablo, Curvetto Néstor
Laboratory of Biotechnology of Edible and Medicinal Mushrooms , Center for Renewable Natural Resources of the Semiarid Region (CERZOS), National Scientific and Technical Research Council (CONICET) and National University of the South (UNS), Bahía Blanca, Argentina .
J Med Food. 2014 May;17(5):543-9. doi: 10.1089/jmf.2013.0108. Epub 2014 Feb 19.
Grifola frondosa, Grifola gargal, and Grifola sordulenta are edible and medicinal mushrooms with antioxidant properties. To obtain wheat flour (Wf ) with a higher antioxidant activity than the one exhibited by regular Wf, solid state fermentation (SSF) of wheat grains with mycelia of those Grifola spp. was used to obtain biotransformed wheat grain (BWG) flour. The methanolic extract of control Wf and BWG flour of G. gargal, G. sordulenta, and G. frondosa (GfWG, GgWG, and GsWG, respectively) were studied for their radical scavenging (RS) activity against 2,2-diphenyl-1-picrylhydracyl (DPPH) and their Fe(III) reducing power (RP). The values for RS-EC50 decreased in BWG flour, therefore presenting a higher antioxidant activity: GgWG (0.56 mg/mL), GfWG (0.81 mg/mL), and GsWG (5.80 mg/mL) in comparison to Wf (57.60 mg/mL). The antioxidant content for this RS activity in terms of ascorbic acid content (RS-EQAA) was highest in GfWG, followed by GgWG and GsWG (71.73, 14.46, and 3.02 mg/g, respectively) and lowest in Wf (0.25 mg/g). The RP-EC50 values in GgWG, GfWG, and GsWG were low (0.55, 0.64, and 4.20 mg/mL, respectively) with respect to Wf (55.00 mg/mL). Compared with Wf (0.56 mg/g), the RP capacity in terms of ascorbic acid content (RP-EQAA) was very high in GfWG (193.67 mg/g) followed by GgWG and GsWG (31.42 and 8.74 mg/g, respectively). The high content in gallic acid equivalents was consistent with RS-EQ(AA) and RP-EQ(AA) contents. TLC revealed that antioxidant activity in BWG could be related to the presence of phenolic compounds. Thus, a valuable food alternative can easily be obtained with wheat grains, that is, by markedly increasing their antioxidant value through SSF with Grifola spp.
云芝、卷边桩菇和污黄多孔菌是具有抗氧化特性的食用和药用蘑菇。为了获得比普通小麦粉具有更高抗氧化活性的小麦粉（Wf），利用这些多孔菌属的菌丝体对小麦籽粒进行固态发酵（SSF）以获得生物转化小麦籽粒（BWG）粉。研究了对照Wf以及卷边桩菇、污黄多孔菌和云芝（分别为GgWG、GfWG和GsWG）的BWG粉的甲醇提取物对2,2 - 二苯基 - 1 - 苦基肼（DPPH）的自由基清除（RS）活性及其还原Fe(III)的能力（RP）。BWG粉中RS - EC50值降低，因此呈现出更高的抗氧化活性：与Wf（57.60 mg/mL）相比，GgWG（0.56 mg/mL）、GfWG（0.81 mg/mL）和GsWG（5.80 mg/mL）。以抗坏血酸含量表示的该RS活性的抗氧化剂含量（RS - EQAA）在GfWG中最高，其次是GgWG和GsWG（分别为71.73、14.46和3.02 mg/g），在Wf中最低（0.25 mg/g）。相对于Wf（55.00 mg/mL），GgWG、GfWG和GsWG中的RP - EC50值较低（分别为0.55、0.64和4.20 mg/mL）。与Wf（0.56 mg/g）相比，以抗坏血酸含量表示的RP能力（RP - EQAA）在GfWG中非常高（193.67 mg/g），其次是GgWG和GsWG（分别为31.42和8.74 mg/g）。没食子酸当量的高含量与RS - EQ(AA)和RP - EQ(AA)含量一致。薄层色谱显示BWG中的抗氧化活性可能与酚类化合物的存在有关。因此，通过利用多孔菌属进行固态发酵显著提高小麦籽粒的抗氧化值，可以轻松获得一种有价值的食物替代品。
