缬草挥发油的提取及抗氧化能力研究

Study on the Extraction for Essential Oil of Valeriana officinalis L. and its Antioxidant Capacity

应用超临界CO2萃取技术,采用正交实验法,对影响缬草挥发油萃取率大小的萃取压力、萃取温度和CO2流量3个因素进行了研究,应用ABTS和FRAP法对缬草超临界CO2提取物的抗氧化能力进行检测,并与水蒸汽蒸馏法得到的缬草挥发油抗氧化能力进行了对比,用紫外分光光度法对超临界CO2萃取及水蒸汽法得到的缬草挥发油中总缬草三酯进行了测定。结果表明:超临界CO2萃取最佳工艺条件为:萃取压力25MPa,CO2流量20L/h,萃取温度55℃,此工艺条件下的缬草挥发油的收率为5.86%,而水蒸汽法收率为1.27%;ABTS和FRAP法下,缬草超临界CO2提取物之间的抗氧化能力差异不显著,但均强于水蒸汽法且差异显著,超临界CO2萃取法得到缬草挥发油中总缬草三酯含量为3.7%,大于水蒸汽法的2.8%,显示超临界CO2萃取法比水蒸汽法更能有效保留缬草挥发油的生物活性成分及生物活性功能。

The essential oils of Valeriana officinalis L. were obtained with supercritical CO2. By using the method of orthogonal experiment, the extraction pressure, extraction temperature and CO2 flow rate were studied. The antioxidant capacities of these es- sential oils were detected with ABTS and FRAP methods, and the comparion were made with that of the essential oil extracted by stream distillation. Total valepotriates were detected by UV Spectrophotometry both for the essential oils extracted by supercritical CO2 and stream distillation. The results show that： For supercritical CO2 extraction, the optimization extraction pressure was 25MPa, temperature was 55℃, and CO2 flow rate was 20L/b. In these process conditions, the extraction rate of essential oil was 5.86%. The extraction rate of essential oil extracted by stream distillation was 1.27%. Both for ABTS and FRAP methods, the antioxidant capacities among these essential oils extracted by supercritical CO2 process were no significant difference. But the an- tioxidant capacities between the essential oils extracted by supercritical CO2 extraction and stream distillation were significant difference. The content of Valepotriates in essential oil extracted by supercritical CO2 was 3.7%, and that extracted by stream distillation was 2.8%. All of these show that the bioactive ingredient and biological activity in the essential oil of Valeriana offici- nctlis L. extracted by supercritical CO2 process were reserved more than these extracted by stream distillation.