Enhancement of antioxidant activity of Radix Puerariae and red yeast rice by mixed fermentation with Monascus purpureus

•The pigment intensity of mixture substrate was 3 times higher than rice.•Total phenolic content and main isoflavones increased after fermentation.•The mixed substrate has higher antioxidant activities.

In this work, a new functional food combined Radix Puerariae and red yeast rice was explored. The pigment intensity, antioxidant activities and the main isoflavones of it were evaluated and compared with traditional red yeast rice and Radix Puerariae. The fermented mixture showed higher contents of isoflavones and pigment intensities than red yeast rice and Radix Puerariae. The DPPH, OH, FRAP and total antioxidant activity results of fermented mixture also showed higher antioxidant potential than those of Radix Puerariae and red yeast rice, owing to the higher pigment intensity and total phenolic contents. It is concluded that the fermented mixture of Radix Puerariae and rice could be widely used as a source of polyphenols with high antioxidative potential, thus introducing numerous health benefits for the consumer.