7种苹果叶多酚的抗氧化性及抗菌性研究

Study on antioxidant and antibacterial activity of apple leaf polyphenols of seven cultivars

为探讨苹果叶多酚抗氧化性及抗菌性,以7个品种苹果成熟叶为试材,采用Folin-ciocalteu法测定总酚含量,FRAP法、DPPH·清除法、超氧阴离子自由基清除法和ABTS＋·法评价体外抗氧化活性,琼脂孔扩散法和最小抑菌浓度（MIC）评价秦冠叶对5种受试致病菌的抑菌性。结果表明：7个品种苹果叶中,秦冠、秦阳和红盖露抗氧化能力较强,密脆、富士、红星和黄元帅较弱。秦冠叶多酚对大肠杆菌、金黄色葡萄球菌、鼠伤寒沙门氏菌LT2的MIC均为25μg/m L,对志贺氏菌和阪崎肠杆菌的MIC为50μg/m L,其抑菌效果明显优于其含有的各种单酚,且抑菌性是茶多酚的3~4倍。从苹果叶中提取的多酚物质是食品抗氧化剂抗菌剂的潜在来源。

In order to investigate the antioxidant and antibacterial activity of apple leaf polyphenols of seven cultivars,total phenolic content was determinated by Folin-ciocalteu method,antioxidant activity was evaluated by ferric-reducing antioxidant power （FRAP） assay, DPPH scavenging assay, superoxide anion scavenging assay and ABTS scavenging assay. The antibacterial activity of Qinguan were evaluated by comparing their minimum inhibitory concentrations（MIC） against five bacterial strains. It was showed that Qinguan exhibited the best antioxidant properties,whereas Qinyang and Gale Gala possessed better antioxidant properties among seven apple cultivars. The strongest antibacterial activity of Qinguan leaf polyphenols was recorded against Escherichia coil, Staphyloccocus aureus, Salmonella typhimurium with MIC value of 25μg/mL,and the lower activity was observed against Shigella and Enterobacter Sakazakii with MIC value of 50μg/mL. Antibacterial activity of Qinguan polyphenols was remarkably better than any monophenol contained in apples,and 3-4 times better than tea polyphenols.