| 摘要: |
| 【目的】研究光照处理对发芽燕麦中多酚类物质含量及抗氧化活性的影响。【方法】将燕麦籽粒分为光照组和黑暗组，浸泡后分别在光照（光照强度为200 μmol/(m2·s)）和遮光条件下进行发芽，在发芽24，48，72和96 h时取样，提取样品中的游离态和结合态多酚，测定多酚、黄酮含量及肉桂酸、阿魏酸、没食子酸、对香豆酸、咖啡酸这5种主要酚酸的组分变化。测定游离态和结合态多酚提取物的抗氧化活性（ABTS、DPPH自由基清除能力和铁还原能力），分析游离态和结合态多酚、黄酮含量与3种抗氧化指标间的相关性。【结果】光照处理下发芽燕麦中游离态和结合态多酚、黄酮含量明显高于黑暗组。游离态多酚提取物中，光照组样品中没食子酸、咖啡酸、阿魏酸含量在发芽过程中总体高于黑暗组，对香豆酸和肉桂酸的含量总体低于黑暗组；5种酚酸的总量在发芽前期（发芽24~48 h）光照组略低于黑暗组，发芽后期（发芽72~96 h）显著高于黑暗组。结合态多酚提取物中，除肉桂酸外，其余4种酚酸的含量在发芽过程中均表现为光照组显著高于黑暗组；在发芽过程中，光照组5种酚酸的总量显著高于黑暗组。光照组样品的游离态和结合态多酚提取物的抗氧化活性均显著高于黑暗组。2种处理下，除游离态黄酮外，发芽燕麦中的多酚、结合态黄酮均与其抗氧化活性间存在显著正相关。【结论】光照处理可有效提高发芽燕麦中多酚物质的含量及其抗氧化活性。 |
| 关键词: 发芽燕麦 光照处理 黑暗处理 多酚类物质 抗氧化活性 |
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| 基金项目:湖南省教育厅一般项目（17C1541）;湖南省教育厅重点项目（19A470） |
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| Effect of light treatments on polyphenols,flavonoids,and antioxidant activities in sprouted oats (Avena nuda L.) |
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DENG Jiaqi,LI Juanjuan,HE Xinyi,et al
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| Abstract: |
| 【Objective】The study explored the effects of light treatment on polyphenols and antioxidant activities in sprouted oats.【Method】Oat grains were soaked before germination under light (200 μmol/(m2·s)) and dark treatments.Samples were taken at 24,48,72 and 96 h after germination and both free and bound polyhenols were extracted to determine contents of polyphenols,flavonoids,and five main phenolic acids (cinnamic acid,ferulic acid,gallic acid,p-coumaric acid and caffeic acid).The antioxidant activities (ABTS,DPPH free radical scavenging ability and iron reduction ability) of both free and bound polyphenol extracts were measured,and the correlations between contents of free,bound polyphenols and flavonoids and three antioxidant indexes were also analyzed.【Result】Contents of free and bound polyphenols and flavonoids in the light group were significantly higher than those in the dark group.In free polyphenol extracts,contents of gallic acid,caffeic acid and ferulic acid in the light group were higher than those in the dark group,while contents of p-coumaric acid and cinnamic acid in the light group was lower than those in the dark group.The total amount of 5 phenolic acids in the light group was slightly lower at early stage (24-48 h of germination) of germination and was significantly higher at late stage (72-96 h of germination) of germination in comparison to that in the dark group.In bound polyphenol extracts,contents of other four phenolic acids were significantly higher in the light group than those in the dark group except cinnamic acid,and the total amount of 5 phenolic acids in the light group was significantly higher than that in the dark group.The antioxidant activities of both free and bound polyphenol extracts of sprouted oats in the light group were significantly higher than those in the dark group.Except for free flavonoids,polyphenols and bound flavonoids had significant positive correlations with antioxidant capacities of ethanol extracts of sprouted oats under light and dark treatments.【Conclusion】Light treatment was an efficient way to increase contents of polyphenols and antioxidant activity in sprouted oat. |
| Key words: sprouted oat light treatment dark treatment polyphenols antioxidant activity |
