Effects of defatted rice bran on the antioxidative activity of effective microorganisms (EM) fermented broth

In the present study, the effects of adding defatted rice bran were investigated to improve the quality of EM fermented broth, which is widely used in agricultural and environmental fields.After culturing EM in medium supplemented with defatted rice bran, the yeast viable counts and antioxidative characteristics of the EM culture medium were measured.Considering the yeast viable counts, polyphenol content, and DPPH radical scavenging activity, the amount of defatted rice bran added was appropriate to be 0.7% or more.With the addition of 0.70% of defatted rice bran, the viable counts of yeast in the EM fermented broth increased by more than 2.54 times from 2.13 × 10 5 to 5.40 × 10 5 CFU/mL, and the contents of polyphenols and flavonoids increased by 5.76 and 2.65 times, respectively.Therefore, the activities (EC 50 ) of scavenging 50% of DPPH and ABTS radicals were significantly decreased to about 20 and 6% of the control group, respectively.The above results indicate that the addition of defatted rice bran may significantly enhance the antioxidative characteristics of the EM fermented broth.