超声辅助水蒸气蒸馏法提取蓝桉叶中精油的工艺优化及其抑菌活性研究

Process optimization and antibacterial activity of extracting essential oil from Eucalyptus globulus leaves by ultrasonic assisted steam distillation

中文关键词:  水蒸气蒸馏  超声辅助  蓝桉叶  精油  抗菌活性

英文关键词:hydrodistillation  ultrasound-assisted  Eucalyptus globulus leaf  essential oil  antimicrobial activity

中文摘要:

      目的 初步探明蓝桉叶精油最佳提取工艺及不同提取工艺条件下蓝桉叶精油得率与其抗菌活性的差异性。方法 以桉叶油得率为评价指标, 采用超声辅助水蒸气蒸馏法, 通过单因素与正交试验确定桉叶油最佳提取工艺。并检验正交试验各组合桉叶油对金黄色葡萄球菌、大肠杆菌和黑曲霉的抑菌效果。结果 桉叶油的最佳提取工艺条件为料液比1:4(g/mL), 超声时间25 min, 超声功率200 W, 蒸馏时间5 h, 桉叶油得率为1.51%。而抑菌试验结果表明, 不同提取工艺所得桉叶油的抑菌活性存在差异。对金黄色葡萄球菌和大肠杆菌而言, 料液比1:6(g/mL), 超声时间30 min, 超声功率180 W, 蒸馏时间5 h时抑菌活性最强, 抑菌圈直径分别为(11.92±0.20) mm(n=3)和(10.25±0.35) mm(n=3), 对应的桉叶油得率为1.28%; 对黑曲霉而言, 料液比1:7(g/mL), 超声时间30 min, 超声功率200 W, 蒸馏时间7 h时抑菌活性最强, 抑菌圈直径为(12.25±0.29) mm (n=3), 对应的桉叶油得率为1.38%。结论 精油得率与其抑菌活性无相关性, 针对不同的目标微生物需要单独优化提取工艺来获得相应的微生物抑菌剂。

英文摘要:

      Objective To explore the optimum extraction technology of Eucalyptus globulus oil and the difference between the yield of Eucalyptus globulus oil and its antibacterial activity under different extraction conditions. Methods Taking the yield of eucalyptus oil as the evaluation index, the optimal extraction process of Eucalyptus oil was determined by single factor and orthogonal test by ultrasonic assisted steam distillation. The antibacterial effects of each combination of Eucalyptus oil on Staphylococcus aureus, Escherichia coli and Aspergillus niger were tested. Results The optimum extraction conditions of Eucalyptus oil were as follows: ratio of material to liquid was 1:4 (g/mL), ultrasonic time was 25 min, ultrasonic power was 200 W, and distillation time was 5 h, and the yield of Eucalyptus oil was 1.51%. The bacteriostasis test results showed that the bacteriostatic activity of Eucalyptus oil obtained by different extraction processes was different. For Staphylococcus aureus and Escherichia coli, the antibacterial activity was the strongest when the ratio of material to liquid was 1:6 (g/mL), the ultrasonic time was 30 min, the ultrasonic power was 180 W, and the distillation time was 5 h. The diameters of the inhibition zone were (11.92±0.20) mm (n=3) and (10.25±0.35) mm (n=3), and the corresponding Eucalyptus oil yield was 1.28%. For Aspergillus niger, the antibacterial activity was the strongest when the ratio of solid to liquid was 1:7 (g/mL), ultrasonic time was 30 min, ultrasonic power was 200 W, and distillation time was 7 h. The diameter of the inhibition zone was (12.25±0.29) mm (n=3), and the corresponding eucalyptus oil yield was 1.38%. Conclusion There is no correlation between the yield of essential oil and its antibacterial activity. For given target, the technological condition of extraction process should be optimized to obtain a corresponding microbial bacteriostatic agent.