Antioxidant Activity and Ferulic Acid Content of Brown Rice Koji and Brown Rice Shio-Koji Prepared Using Three Species of Koji Molds

For the purpose of improving rice functionality by effectively utilizing rice bran, brown rice (BR) koji and BR shio-koji were prepared using three species of koji molds and their antioxidant activities were investigated. The antioxidant activities of the three BR koji were higher than that of BR, and that of the BR koji of Aspergillus luchuensis (AL) was the highest. AL-BR koji contained about 250 times more ferulic acid, an antioxidant component, than BR, and the used AL showed high feruloyl esterase (FAE) activity. However, the ferulic acid content of AL-BR shio-koji was lower than that of AL-BR koji, and the FAE of AL was inhibited by NaCl.