Abstract: In this study,quantitative and qualitative analyses were carried out for screening of antioxidant substance in Noni (Morinda citrifolia L,Rubiaceae)ferment ation juice.The chemical components of the different fractions eluted from macroporous resin HP-20 were preliminary analyzed.The content of phenols and antioxidant activity were evaluated through Folin-Ciocalteu method,DPPH·and ABTS+·scavenging rates and Ferric-reducing antioxidant power assays.The results showed the active fractions located in the 50%-90% ethanol eluted fractions,which were composed of phenols,flavonoids,coumarins and anthraquinone.Significant correlation between phenols content and antioxidant activity suggested that noni fermentation juice had strong antioxidant activity,and the phenols were the main functional components and potential of acting as natural antioxidant.

Key words: Noni fermentation juice, quantitative and qualitative analyses, phenols, antioxidant