Functional components and antioxidant activity of okara fermented by Cordyceps militaris

Cordyceps militaris was used to fermented okara in solid state fermentation, and the change in functional ingredients and the antioxidant activity of fermented okara was tested.Okara was fermented by Cordyceps militaris for 7 days, the content of cordycepin, total phenlic and polysaccharide were tested. In addition, DPPH scavenging activity, reducing power, fluorescence recovery after photobleaching ( FRAP) and ABTS⁺·scavenging activity were tested to study the antioxidant activity of fermented okara.The relation between functional ingredients and antioxidant index were researched by the correlation analysis and principal component analysis.Results showed that the content of polysaccharide, cordycepin and total phenolic of water extracts were ( 236.16 ± 39.91) , ( 1.88 ± 0.04) μg/mg and ( 11.94 ± 0.33) μg GAE/mg. Compared to the control, the content of polysaccharide and total phenolic were increased by 1.42, 2.15-fold respectively.The concentration of the extract was 6 μg/mg, DPPH free radical scavenging capacity increased from 24.63% to 72.4%, reducing power increased from 0.11 to 0.38, ABTS⁺·radical scavenging capacity increased from 76.76% to 88.71%, FRAP from 39.08 μmol/L to 269.55 μmol/L. The principal component analysis and correlation analysis showed that the antioxidant index and polysaccharide, cordycepin and total phenolic had a significant correlation ( p < 0.01) . Thus, this study showed that fermented okara with enhanced functional ingredientsand antioxidant activities can be developed as food contained cordycepin and antioxidants.