巴西蕉花蕾不同部位提取物的抗氧化活性研究

Antioxidant Activity of Ethanol Extracts from Different Tissues of Banana (Musa AAA Cavendish subgroup cv.Brazil) Inflorescence

评价巴西蕉花蕾不同部位的化学组成和乙醇提取物的抗氧化活性。结果表明:3个部位中花的总黄酮含量最高(5.9mg/100g),苞片的总酚含量最高(14.91mg/g),生长点的皂苷含量最高(14.77mg/100g)。3部位提取物均具有一定的清除DPPH自由基、ABTS+自由基、还原力和脂质过氧化抑制作用,且清除率和质量浓度间存在剂量依赖关系。其中,苞片具有最强的清除DPPH自由基、ABTS+·、还原力和抑制脂质过氧化的作用,生长点次之;3部位乙醇提取物的还原力均比没食子酸强。

The 70% ethanol extracts from three different tissues of banana （Musa AAA Cavendish subgroup cv.Brazil） inflorescence including petal,bract and growth point were assessed for their free radical scavenging and anti-lipid peroxidation activities and reducing power.Among the three tissues of banana inflorescence,the highest contents of total flavonoids （5.9 mg/100 g）,total phenolics （14.91 mg/g） and saponins （14.77 mg/100 g） were found in petals,bracts and growth points,respectively.All the extracts from them could scavenge DPPH and ABTS^＋ free radicals and protect against lipid peroxidation and had pronounced reducing power in a concentration-dependent fashion and the extract from banana bracts had the strongest ability to scavenge DPPH and ABTS^＋ free radicals and reducing power and anti-lipid peroxidation activity,followed by that from banana growth points.Furthermore,compared with galic acid,all the extracts from banana petal,bract and growth point presented higher reducing power.