金银花粗多糖提取工艺优化及其抗氧化活性评价

采用热水提取法提取金银花多糖,通过单因素实验考察料液比、浸提时间、浸提温度和提取次数4个因素对多糖得率的影响,在此基础上利用响应面法对提取条件进行优化。以DPPH自由基、ABTS⁺自由基、羟基自由基、超氧阴离子自由基清除能力和总还原力为指标评价金银花粗多糖的抗氧化活性。结果表明:金银花多糖的最佳提取工艺条件为料液比1:30(g/mL)、浸提时间120 min、浸提温度70℃,此条件下多糖的实际得率为6.45%±0.15%,与预测值的相对误差为1.2%。当金银花粗多糖浓度为2 mg/mL时,DPPH自由基、ABTS⁺自由基、羟基自由基和超氧阴离子自由基的清除率分别为88.56%、99.51%、46.40%和85.88%,总还原力为1.04。该方法制备的金银花粗多糖具有较好的抗氧化能力,这为金银花活性多糖的进一步分离、纯化及结构表征提供了理论依据。

Extraction Process Optimization and Antioxidant Activity Evaluation of Crude Polysaccharides from Lonicera japonica

The polysaccharides from Lonicera japonica were extracted by the hot water extraction method, and the effects of solid-liquid ratio, extraction time, extraction temperature and extraction times on the yield of polysaccharides were investigated by a single factor test. On this basis, the response surface method was used to optimize the extraction conditions. The antioxidant activity of crude polysaccharides from Lonicera japonica were evaluated by measuring DPPH free radical, ABTS+ free radical, hydroxyl free radical, superoxide anion free radical scavenging ability and total reducing power. The results showed that the optimal extraction process conditions of polysaccharides from Lonicera japonica were as follow: solid-liquid ratio of 1:30 (g/mL), extraction time of 120 min, and extraction temperature of 70 ℃. Under these conditions, the actual yield of polysaccharides from Lonicera japonica was 6.45%±0.15%, and the relative error with the predicted value was 1.2%. When the concentration of crude polysaccharides was 2 mg/mL, the maximum scavenging rates of DPPH free radical, ABTS+ free radical, hydroxyl free radical and superoxide anion free radical were 88.56%, 99.51%, 46.40% and 85.88%, respectively. Besides, the total reducing power was 1.04. The optimized crude polysaccharides had an excellent antioxidant activity, which provided a theoretical basis for further isolation, purification and characterization of active polysaccharides from Lonicera japonica.