体外模拟消化对苹果多酚及其抗氧化活性的影响

Effects of in vitro simulated digestion on apple polyphenols and their antioxidant activities

利用体外模拟消化模型研究胃肠消化对苹果多酚及其抗氧化活性的影响。以总酚及主要酚类物质的含量变化来评价胃肠消化对苹果多酚的影响,以DPPH和ABTS自由基清除能力、铁离子还原能力(ferric reducing antioxidant power,FRAP)、氧自由基吸收能力(oxygen radical absorbance capacity,ORAC)为指标,评价苹果多酚提取物在胃肠消化过程中抗氧化活性的变化。在胃消化过程中总酚含量随着消化时间延长而增加,在肠消化过程中总酚含量随着消化时间延长先增加后减少,但均低于消化前样品中的含量;在胃消化液中可检测到的主要酚类物质按照含量由高到低依次为绿原酸、表儿茶素、咖啡酸、儿茶素;在肠消化液中可检测到的主要酚类物质仅有绿原酸;胃肠消化使主要酚类物质发生降解或转化;胃肠消化显著提高苹果多酚提取物对DPPH自由基和ABTS自由基清除能力、铁离子还原能力及氧自由基吸收能力;胃肠消化过程中总酚含量与以DPPH、ABTS、ORAC法测定的抗氧化活性高度相关,与FRAP法测定的抗氧化活性相关性不高。胃肠消化导致酚类物质降解或转化,在一定程度上增强了其抗氧化能力。

In this study,the effects of gastrointestinal digestion on apple polyphenols and their antioxidant activity were detected using an in vitro simulated digestion model.The effects were estimated based on the changes of total and main phenolic content and the antioxidant activity of apple polyphenols was evaluated on the basis of DPPH and ABTS free radical scavenging ability,ferric reducing antioxidant power(FRAP)and oxygen radical absorbance capacity(ORAC).The results showed that total phenolic content increased with the prolongation of digestion during gastric digestion.Total phenolic content during intestinal digestion increased firstly and then decreased when digestion time was prolonged.But the total phenolic content during gastric and intestinal digestion was lower than that of before the digestion treatment.The main phenolic components in gastric digestion were chlorogenic acid,epicatechin,caffeic acid and catechin in order from high to low.However,in intestinal digestion only chlorogenic acid could be detected.Gastrointestinal digestion may cause degradation or transformation of major phenolic components.After gastric and intestinal digestion,DPPH and ABTS radical scavenging capacity,FRAP and ORAC values significantly increased.During gastrointestinal digestion,the total phenol content was highly correlated with the antioxidant activities measured by DPPH,ABTS,and ORAC except FRAP.It was illuminated that gastrointestinal digestion resulted in the degradation or conversion of phenolic components and the increasing of antioxidant capacity to some extent.