二氧化碳超临界萃取山苍子油及其抗氧化效能测定

应用二氧化碳超临界萃取法提取山苍子油，以正交设计法考察萃取温度、压力、流量、时间对提取效率的影响，与此同时，以DPPH法测定山苍子油的抗氧化活性，并首次研究了夹带剂使用与不同提取时段对山苍子油提取率及其抗氧化效能的影响．结果表明：在50℃、25MPa压力和40L／h流量时，油得率可高达36．7％；单位时间内山苍子油得率随着时间推延呈锐减趋势，第1时段（0～20min）占总出油量的80．86％～97．11％；但从抗氧化效能看，第2时段（20～40min）得到的山苍子油透明度高，抗氧化效果也明显优于前者；在超临界萃取过程中加入夹带剂可以显著提高山苍子油得率及山苍子油的抗氧化活性，以乙酸乙酯为夹带剂，萃取率最高可达45．88％；以甲醇为夹带剂时，山苍子油的抗氧化活性达到最佳值，DPPH法测得IC50仅为0．30g／L，而对照组IC50。为7．63g／L．

Supercritical Carbon Dioxide Extraction of Oil from Litsea Cubeba and the Antioxidant Activity Test of the Oil

Extraction of volatile oils from the dry fruits of Litsea cubeba with supercritical carbon dioxide was studied. The influence of temperature, pressure, CO2 flow rate and time on the efficiency of extraction was examined by orthogonal experiment. Meantime, the antioxidant activity of Litsea cubeba oil was measured by the DPPH test, and it was studied for the first time bow the application of co-solvent and the extraction time can affect the rate of extraction and the oil＇s antioxidant activity. The results show that the optimal extracting conditions are determined as pressure 25 MPa, temperature 50℃, CO2 flow rate 40 L/h, with largest extraction rate of volatile oils as 36.7 %. The extraction time can make big difference on that from the first 20 min. It is proved that adding the co-solvent can improve extract＇s total yield and antioxidant activity. The extraction rates can reach 45.88 % when acetic ether used as co-solvent. The best antioxidant activity can be achieved when methyl alcohol is used as co-solvent, with the IC50 measured by DPPH method as low as 0.30 g/L, compared with 7.63 g/L of CK.