Abstract:To explore the changes of polyphenols and flavonoids content and antioxidant activity during in vitro simulated gastrointestinal digestion of kiwifruit(pulp and juice), the antioxidant activity was evaluated by the ferric reducing antioxidant power assay and the radical scavenging capacity of DPPH, superoxide anion and hydroxyl. The results showed that the release of polyphenols and flavonoids increased after digestion. For kiwifruit pulp, the maximum amounts of polyphenols and flavonoids were 1.62 and 2.40 times of that before digestion, while 1.63 and 2.90 times for juice. The radical scavenging rates of DPPH, superoxide anion and hydroxyl, as well as ferric reducing antioxidant power of juice and pulp reached the maximum after 1 h digestion, then declined and gradually stabilized. Different antioxidant capacity with similar variation of pulp and juice is observed. Studies indicate that simulated gastrointestinal digestion can promote the release of polyphenols and flavonoids, and improve antioxidant activity.
