To make a good use of rice bran that has been treated as a kind of industri
al waste, we have tried to ferment the rice bran by typical microorganisms
such as yeast, and to extract ingredients with antioxidative activity. The
antioxidative activity was estimated as a SOD-like activity. The SOD-like a
ctivities of the rice bran extracts after fermentation by using ESR spectro
scopy by baker's yeast and whisky yeast significantly increased in comparis
on with that of rice bran extract without fermentation. The components in t
he rice bran extracts after fermentation participating in the SOD-like acti
vity were suggested to be kinds of protein. We estimated the molecular weig
hts of the proteins precipitated with ammonium sulfate, using a HPLC. Based
on the results obtained from the HPLC measurements, the proteins with a SO
D-like activity various molecular weights exist in rice bran extracts after
fermentation. The proteins with a SOD like activity map be composed with t
he other components such as polyphenol and sugar, having a SOD-like activit
y.