石榴叶多糖亚临界水提取工艺的优化及其体外抗氧化活性

Optimization of subcritical aqueous extraction for polysaccharides from Punica granatum leaves and the in vitro antioxidant activity

目的优化石榴Punica granatum L.叶多糖亚临界水提取工艺,并评价其体外抗氧化活性。方法在单因素试验基础上,以反应压力、料液比、提取时间、提取温度为影响因素,多糖得率为评价指标,Box-Behnken法优化提取工艺。再检测多糖对羟自由基、超氧阴离子、DPPH自由基的清除作用。结果最佳提取条件为反应压力5 MPa,料液比1∶27,提取时间11 min,提取温度155℃,多糖得率1.809%。清除率与多糖质量浓度呈量效关系,0.1 mg/m L多糖对羟自由基、超氧阴离子、DPPH自由基的清除作用最强,清除率分别为57.36%、70.51%、58.02%。结论该方法稳定可靠,可用于亚临界水提取有明显体外抗氧化活性的石榴叶多糖。

AIM To optimize the subcritical aqueous extraction for polysaccharides from the leaves of Punica granatum L.and to evaluate the in vitro antioxidant activity.METHODS With reaction pressure,solid-liquid ratio,extraction time and extraction temperature as influencing factors,yield of polysaccharides as an evalution index,the extraction was optimized by Box-Behnken method on the basis of single factor test.Then the scavenging effects of polysaccharides on hydroxyl free radical,superoxide anion and DPPH free radical were detected.RESULTS The optimal conditions were determined to be 5 MPa for reaction pressure,1 ∶ 27 for solid-liquid ratio,11 min for extraction time,and 155 ℃ for extraction temperature,the yield of polysaccharides was 1.809%.There was a dose-effect relationship between scavenging rate and polysaccharides＇ concentration.0.1 mg/m L Polysaccharides displayed the strongest scavenging effects on hydroxyl free radical,superoxide anion and DPPH free radical with the clearance rates of 57.36%,70.51% and 58.02%,respectively.CONCLUSION This stable and reliable method can be used for the subcritical aqueous extraction for polysaccharides from P.granatum leaves with obvious in vitro antioxidant activity.