甘薯叶片的抗氧化活性和相关成分比较

为了选育保健型菜用甘薯品种，以海南地区栽种的10个甘薯品种为材料，对叶片中3种色素（花青素、叶绿素、类胡萝卜素）、总酚和总黄酮含量进行测量，通过分析各指标与代表抗氧化性的ABTS（2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)、2,2′?联氮?双?3?乙基苯并噻唑啉?6?磺酸）、DPPH（2,2′-diphenyl-1-picrylhydrazyl，2,2′?二苯基?2?三硝基苯肼）自由基清除能力的关联性，综合分析甘薯叶片的抗氧化成分及抗氧化活性。结果表明，不同甘薯品种叶片的抗氧化活性与总黄酮、花青素含量呈极显著正相关（P < 0.01），与叶绿素含量呈显著正相关（P < 0.05），与总酚含量呈正相关但未达到显著相关水平（P > 0.05）。甘薯‘福薯7-6’的叶绿素和类胡萝卜素含量较高，但总酚、总黄酮和花青素含量低，抗氧化活性最低；‘渝15’和‘徐紫菜8’叶片的总酚、总黄酮和花青素显著高于其他8个品种，抗氧化活性最高。在选育保健型菜用甘薯时，可根据叶片颜色初步判断其抗氧化性能，降低育种成本。

Antioxidant Activities of Sweetpotato Leaves and Comparison of Their Related Components

In order to select sweetpotato varieties with healthy leaves as vegetables in Hainan Province, 10 sweetpotato varieties were comprehensively evaluated in terms of leaf antioxidant activities. The leaf contents of three pigments (chlorophylls, carotenoids, and anthocyanins), total phenolics and total flavonoids were determined, and the ABTS (2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) and DPPH (2,2′-diphenyl-1-picrylhydrazyl) radical scavenging abilities, which directly represent antioxidant activities, were also detected in the leaves. The results showed that the leaf antioxidant activities in all the sweetpotato varieties were positively correlated with the leaf contents of total flavonoids (P < 0.01), anthocyanins (P < 0.01), chlorophylls (P < 0.05), and total phenolics (P > 0.05).The vegetable sweetpotato variety ‘Fushu 7-6’ was higher in the contents of chlorophylls and carotenoids, but lower in the contents of total flavonoids, total phenolics and anthocyanins, and hence was the lowest in the antioxidant activity among the 10 sweetpotato varieties. Sweetpotato varieties ‘Yu 15’ and ‘Xuzicai 8’ had significantly higher leaf contents of total phenols, total flavonoids and anthocyanins than the other 8 sweetpotato varieties, and were the highest in antioxidant activity. The red color of the leaves of sweetpotato varieties indicated higher antioxidant activity in the leaves, based on which sweetpotato varieties with healthy leaves as vegetables can be selected to reduce the breeding cost.