分蘖洋葱鳞茎总黄酮提取工艺及抗氧化活性

以分蘖洋葱‘M-3’鳞茎为试材,用超声波辅助提取黄酮类化合物,在单因素试验基础上,采用Box-Behnken响应面法优化分蘖洋葱总黄酮提取工艺,用DPPH法对总黄酮化合物抗氧化活性进行评价。结果表明:最佳提取工艺参数为料液比1∶45 g·mL^-1、乙醇体积分数60%、提取时间40 min、提取温度48℃、超声波功率310 W。在该条件下,分蘖洋葱总黄酮的提取率为3.584%,与模型预测值3.622%相近。分蘖洋葱总黄酮提取物对DPPH·具有一定的清除作用,IC50值为0.179 mg·mL^-1。优选的超声波提取工艺提高了分蘖洋葱总黄酮提取率,具有较强的抗氧化活性。

Extraction Process and Antioxidant Activity of Total Flavonoids From the Bulbs of Multiplier Onion(Allium cepa L. var. Aggregatum G. Don)

Taking the bulbs of’M-3’multiplier onion(Allium cepaL.var.Aggregatum G.Don)as test material,on the basis of single factor experiment,the optimum ultrasound-assisted extraction process of total flavonoids from bulbs was analyzed by using Box-Behnken design(BBD)with response surface methodology.The antioxidant activity of total flavonoids was evaluated by DPPH method.The results showed that the optimal extraction conditions were determined as follows:1∶40 g·mL^-1 of solidliquid ratio,60%of ethanol volume fraction,50℃of extraction temperature,300 W of ultrasonic power,30 minutes of extraction time.Under these conditions,the exaction rate of total flavonoids from the bulbs of multiplier onion was 3.586%,which was closed to the model predicted value of 3.622%.The antioxidant tests showed the total flavonoids had a scavenging effect on DPPH·.The IC50 value was 0.179 mg·mL^-1 which indicated that the flavonoids from multiplier onion bulbs has strong antioxidant activity.The optimal ultrasonic-assisted extraction process improved the extraction rate of total flavonoids from the bulbs of multiplier onion,and the extracts by this process also exhibited a better antioxidant activity.