紫玉兰叶总黄酮的提取工艺优化及对亚硝酸盐清除能力研究

Extraction process optimization of total flavonoids from Magnolia liliiflora leaves and ability of scavenging nitrite

为提高紫玉兰资源的利用率,本研究探究了超声波对紫玉兰叶总黄酮提取率的影响,并采用响应面法对提取条件进行了优化。之后对总黄酮提取物对亚硝酸盐的清除能力进行了评价。通过单因素试验,再应用Box-Behnken试验设计,将紫玉兰叶总黄酮设为响应值,分别选取超声温度、液料比、乙醇浓度和超声时间4个因素进行4因素3水平的响应面试验,并建立二次回归方程模型。结果表明:紫玉兰叶总黄酮的最佳提取工艺条件是:超声温度64℃、液料比36 mL/g、乙醇浓度63%和超声时间29 min,在上述条件下进行3次重复试验,得到的总黄酮平均提取率为95.72 mg/g,该数值与预测值的相对误差仅有0.26%,说明该模型合理,预测可靠。所提取的总黄酮展现了对亚硝酸盐具有较强的清除能力,并与亚硝酸盐清除能力呈良好的量效关系,当质量浓度为6.0 mg/L时,对亚硝酸盐的清除率达到74.21%。

To improve resource utilization of Magnolia liliiflora,this study used response surface method to optimize ultrasonic extraction conditions of total flavonoids from M.liliiflora leaves.The effect of total flavonoids on scavenging nitrite was further investigated.In the extraction experiments,single factor experiments were firstly conducted,with flavonoid extraction rate as the response value,then the experiment of Box-Behnken design of four factors(extraction temperature,liquid-solid radio,ethanol concentration,and extraction time)and four levels was performed,and the regression equation model was established.The result showed that the optimized ultrasonic extraction conditions were:64℃extraction temperature,36 mg/L liquid-solid ratio,63%ethanol concentration,and 29 min extraction time.Under this condition,the average total flavonoid extraction rate reached 95.72 mg/g,which was close to the predicted value of the regression equation,and the relative standard deviation was only 0.26%,indicating that the established regression model was reasonable.The total flavonoid extract possessed high ability of scavenging nitrite and exerted a concentration-dependent manner,which 74.21%scavenging rate on nitrite was found at 6 mg/L total flavonoid extract.