Dynamic change and antioxidant activity of phenolics in the mulberry leaf and Jinhua tea

This paper aims to investigate the dynamic change and antioxidant activity of water soluble phenolic substances in mulberry leaves and Eurotium cristatum solid bi-directional fermentation process. The contents of the water soluble total flavonoids and total phenolics were measured by using Al Cl3 method and Folin-Ciocalteu method. At the same time, the antioxidant activity changes of the solid bi-directional fermentation process were evaluated by three in vitro experiments including DPPH assay, ABTS+assay and ferric-reducing power assay. The results showed that during the fermentation process, the water soluble total flavonoids and total phenolics decreased after the initial increase. The water soluble flavonoid content after 14 days' fermentation was the highest,being 2.16 mg/g, and the water soluble phenolics content after 20 days' fermentation was the highest, being 1.48 mg/g. The antioxidant activity displayed an order of 14 d7 d11 d20 d40 d.