发酵对莜麦多酚及抗氧化活性生物可及性的影响

为了提高莜麦中多酚及抗氧化活性的生物可及性，采用体外模拟消化模型和结肠发酵模型，对比了发酵莜麦和未发酵莜麦在不同消化阶段以及结肠发酵阶段总酚含量及抗氧化活性的变化规律，并进一步对其生物可及性进行探究。结果显示：体外模拟消化阶段，除还原力外，不同处理莜麦中的多酚及自由基清除生物可及性的顺序依次为：小肠 ? 胃 ? 口腔；与未发酵莜麦相比，发酵莜麦消化后多酚生物可及性提高22.75%，DPPH自由基清除生物可及性提高48.30%，羟自由基清除生物可及性提高11.77%，还原力生物可及性提高59.20%。结肠发酵阶段，除羟自由基生物可及性外，发酵莜麦消化残渣多酚及抗氧化活性的生物可及性均高于未发酵莜麦消化残渣；与未发酵莜麦相比，发酵莜麦消化残渣多酚生物可及性高36.3%，DPPH自由基清除力生物可及性高16.9%，还原力生物可及性高23.1%。研究结果表明发酵能显著提高莜麦多酚及抗氧化活性在胃肠消化道中的生物可及性，并能提高多酚等抗氧化组分在结肠发酵中的生物可及性。

Effects of Fermentation on Antioxidant Activities and Bioaccessibility of Polyphenols in Naked Oats

In order to improve the bioaccessibility of polyphenols and antioxidant activity in naked oats, the in vitro simulated digestion model and colonic fermentation model were used. The changes of total phenol content and antioxidant activity of fermented and unfermented naked oat at different digestion stages and colonic fermentation stages were compared, and the bioaccessibility was further explored. The results showed that except for reducing power, the order of total phenol content and antioxidant activity was as follows: intestine ? stomach ? oral cavity at the simulated digestion stage in vitro. Compared with unfermented naked oats, the bioaccessibility of polyphenols, DPPH free radical scavenging, hydroxyl free radical scavenging, and reducing power were increased by 22.75%, 48.30%,11.77%, and 59.20%, respectively, infermented naked oat after digestion. At the colonic fermentation stage, except for the hydroxyl free radical bioaccessibility, the bioaccessibility of polyphenols and antioxidant activities in fermented oat were higher than that of unfermented naked oat digestive residue. Compared with unfermented naked oat, polyphenol bioaccessibility of fermented naked oat digestive residue was 36.3% higher, DPPH free radical scavenging bioaccessibility was 16.9% higher, and reduction bioaccessibility was 23.1% higher. The results indicated that fermentation could significantly improve the bioaccessibility of naked oats polyphenols and antioxidant activities in the gastrointestinal tract, but also improve the bioaccessibility of antioxidant components in colon fermentation.