体外模拟胃肠消化过程中猕猴桃抗氧化成分及活性的变化

研究猕猴桃果浆和果汁在体外模拟胃肠消化过程中多酚黄酮类物质含量及抗氧化活性的变化规律。采用铁还原力，以及DPPH自由基、超氧阴离子自由基、羟自由基清除法测定抗氧化性。结果显示，消化后多酚和黄酮物质释放量增加。果浆消化后最大释放量分别为消化前的1.62倍和2.40倍；果汁消化后多酚、黄酮的最大释放量分别是消化前的1.63倍和2.90倍。果汁、果浆的DPPH自由基、超氧阴离子自由基和羟自由基清除率以及铁还原力均在模拟胃消化1 h和肠消化1 h后达到最大值，随后开始下降并趋于稳定。果浆和果汁的抗氧化能力虽不同，但变化规律类似。研究表明，模拟胃肠消化能促进猕猴桃多酚、黄酮的释放，提高抗氧化活性。

Changes of Antioxidant Components and Activities in Kiwifruit after Simulated Gastrointestinal Digestion in vitro

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.