石榴叶总黄酮的提取工艺及抗氧化活性考察

目的:优化石榴叶总黄酮的提取工艺,并对其体外抗氧化活性进行评价,为该部位的开发提供参考。方法:在单因素试验基础上,选择乙醇体积分数、料液比、超声功率、超声时间为考察因素,石榴叶总黄酮提取率为评价指标,根据BoxBehnken设计原理,采用响应面法优化石榴叶总黄酮的提取工艺。通过DPPH和·OH的清除能力考察石榴叶总黄酮的体外抗氧化活性。结果:石榴叶总黄酮最佳超声提取工艺为乙醇体积分数59.8%,料液比1∶16.3,超声功率221 W,提取时间33.45 min;石榴叶总黄酮提取率0.433%,与理论值偏差很小。当样品质量浓度为0.6~1.0 g·L-1时,对DPPH和·OH清除率较高,与维生素C接近。结论:优选的提取工艺稳定可行、提取率高,石榴叶总黄酮抗氧化性能较强,为该部位的工业化生产提供参考。

Optimization of Extraction Technology and Investigation of Antioxidant Activity of Total Flavonoids from Punica granatum Leaves

Objective: To optimize extraction process of total flavonoids from Punica granatum leaves by response surface methodology and investigate its in vitro antioxidant activity. Method: On basis of single factor tests and Box-Behnken principle,response surface methodology was used to optimize extraction conditions with ethanol concentration,solid-liquid ratio,ultrasonic power and time as factors,yield of total flavonoids as index.DPPH and·OH scavenging assays were carried out to verify in vitro antioxidant activity of total flavonoids from P. granatum leaves. Result: Optimum extraction conditions were ethanol concentration of 59.8%,solid-liquid ratio of 1 : 16.3,ultrasonic power of 221 W,extraction time of 33.45 min;under these conditions,yield of total flavonoids was 0.433%.When the concentration of sample was 0.6-1.0 g·L^-1,scavenging rates of DPPH radical and·OH were high,which approached vitamin C. Conclusion: Application of this simple and workable technology to extract total flavonoids from P. granatum leaves can improve extraction efficiency,total flavonoids shows a relatively high antioxidant activity.