Effect of Fermentation on the Antioxidant Activity of Rice Bran by Monascus pilosus KCCM60084

Abstract

In this study, we optimized fermentation conditions for the solid state fermentation of rice bran with Monascus pilosus KCCM60084, and the antioxidant activities were investigated. Optimal fermentation conditions were determined by the production of Monacolin K, a functional secondary metabolites with cholesterol lowering activity. The highest Monacolin K production were 2.88 mg/g observed on day 10 with 45% moisture content in the substrate when inoculated with 5% inoculum (w/w). Reducing power, iron chelating activity and <TEX>$ABTS^+$</TEX> radical scavenging activity were significantly enhanced after fermentation by 60, 80, and 38% respectively. Furthermore, the content of total flavonoid were found to be increased by 4.58 fold. Based on these results, Monascus-fermented rice bran showed strong possibility to be used as a natural antioxidant agent due to its enhanced antioxidant activity.