体外模拟消化过程中核桃花提取物抗氧化活性的变化

Changes of in Vitro Simulated Gastrointestinal Digestion on the Antioxidant Activity of Walnut Flower

为研究体外模拟消化过程中核桃花提取物抗氧化活性的变化,对核桃花提取物依次进行模拟口腔消化、胃消化和小肠消化,分别采用福林酚法和亚硝酸钠-硝酸铝法测定核桃花提取物在不同消化阶段的总酚和总黄酮含量,以DPPH自由基、ABTS自由基清除能力和铁还原能力为指标,考察核桃花提取物抗氧化活性的变化情况。结果表明:在口腔消化、胃消化和小肠消化过程中,核桃花提取物的总酚、总黄酮含量以及抗氧化活性均呈下降趋势。其中总酚含量从消化前的3.30 mg/mL降至消化后的0.62 mg/mL,降低了81.21%;总黄酮含量从2.88 mg/mL降至0.02 mg/mL,降低了99.31%;核桃花提取物清除DPPH自由基的IC50值从211.02μg/mL上升到424.45μg/mL,清除ABTS自由基的IC50值从220.63μg/mL上升至421.82μg/mL,铁还原能力从106.13μg/mL下降为40.47μg/mL。在模拟胃消化和小肠消化阶段,酸碱环境和消化酶的作用破坏了核桃花提取物中的抗氧化成分,使其抗氧化活性发生了显著下降。

To investigate the influence of in vitro digestion on the antioxidant component and activity of walnut flower,the walnut flower extract(WFE)was subjected to mimic mouth,gastric and gastrointestinal digestion.The total phenolic content(TPC)and total flavonoid content(TFC)of WFE were determined by folin-ciocalteu method and sodium nitrite-aluminum nitrate colorimetric method.Antioxidant activities of WFE were evaluated using DPPH radical scavenging capacity,ABTS radical scavenging capacity,and ferric reducing antioxidant power(FRAP)assays.Results showed that TPC,TFC and antioxidant activity of WFE decreased during oral,gastric and intestinal digestion.After digestion,TPC decreased by 81.21%(from 3.30 to 0.62 mg/mL),while TFC decreased by 99.31%(from 2.88 to 0.22 mg/mL).The simulated digestion significantly decreased the antioxidant activity of WFE,the IC50 value increased from 211.02 to 424.45μg/mL for DPPH radical scavenging activity,from 220.63 to 421.82μg/mL for ABTS radical scavenging activity,and from 106.13 to 40.47μg/mL for FRAP value.In the stage of gastric and intestinal digestion,the acid and alkali environment and digestive enzymes destroyed the antioxidant components of WFE,which led to a significant reduction in the antioxidant activity.