沙棘果渣总黄酮提取工艺及抗氧化活性分析

利用超声波辅助提取技术对河西走廊沙棘榨汁提油后的果渣下脚料总黄酮提取工艺进行优化，同时考察果渣黄酮提取液的还原力和清除羟自由基和超氧阴离子自由基的能力。通过单因素试验和L9（34）正交试验，得到影响黄酮得率的主要因素及其影响力大小为乙醇体积分数＞提取时间＞料液比；确定最佳提取条件为乙醇体积分数60%、提取时间40 min、料液比1∶50（g/mL）；此条件下，河西走廊沙棘果渣中总黄酮提取率为2.55%，果皮渣中总黄酮提取率为0.651%，沙棘籽粕中总黄酮提取率为1.901%。当质量浓度大于0.151 4 mg/mL时，沙棘果渣黄酮提取液的还原力大于VC的还原力；沙棘果渣黄酮提取液对羟自由基和超氧阴离子自由基均有一定的清除作用，其对羟自由基的清除率为39.07%～42.01%，大于同等质量浓度VC的清除作用，而对超氧阴离子自由基的清除率为47.17%～60.38%，小于同等质量浓度VC的清除作用，说明沙棘果渣黄酮提取液对羟自由基有更强的清除能力。

Extraction and Antioxidant Activity of Total Flavonoids from Sea Buckthorn Pomace

The aim of the current study was to optimize the extraction conditions for total flavonoids from sea buckthorn
(Hippopphae rhamnoides L.) pomace (the leftover residue from juice making) by orthogonal array design. The antioxidant
activity of the total flavonoids extracted was assessed by hydroxyl radical and superoxide anion radical scavenging,
and reducing power assays, respectively. Ethanol concentration, extraction time and the ratio of material to solvent
were identified as three main variables that affect extraction efficiency by signal factor experiments, and these factors
were further optimized to be 60%, 40 min and 1:50 (g/mL), respectively, using orthogonal array design. Under the
optimized conditions, the predicted extraction yield of total flavonoids from sea buekthom pomace was 2.55%. The
total flavonoids had strong reducing power, and exhibited a more powerful scavenging effect against superoxide anion
radical than against hydroxyl radical.