超声-微波辅助提取柑橘皮精油工艺及抗氧化活性研究

Study on ultrasonic-microwave assisted extraction of essential oil from citrus peel and its antioxidant activity

为提高柑橘皮精油的提取率,采用超声-微波协同辅助水蒸馏法提取柑橘皮精油,利用响应曲面法对提取工艺进行优化,通过气相色谱-质谱联用比较超声-微波协同辅助水蒸馏和直接水蒸馏组分差异,评价了其抗氧化活性和抗菌活性。结果表明:经响应曲面法优化后柑橘皮精油最佳提取条件是,料液比为1∶20、超声功率为300 W、微波功率为310 W和超声-微波时间为120 s,此时的提取率高达3.99%,高于直接水蒸馏法的2.82%;超声-微波辅助水蒸馏法的精油中的D-柠檬烯和月桂醛含量降低,而α-蒎烯、芳樟醇、α-松油醇、癸醛和(Z)-石竹烯等含量增加;超声-微波辅助水蒸馏法精油对DPPH清除率明显增加,但对大肠杆菌抑制作用无明显差异。结论:超声-微波辅助明显提高柑橘皮精油提取率,增强精油抗氧化活性。

In order to improve the extraction yield of citrus peel essential oil,ultrasonic-microwave assisted hydrodistillation was used.Response surface analysis method was used to optimize extraction process.The components of ultrasonic-microwave assisted hydrodistillation and direct hydrodistillation were compared by gas chromatograph-mass spectrometer(GC-MS),and the antioxidant and antibacterial activities were evaluated.The results showed that the optimized extraction conditions of citrus peel essential oil are:The ratio of material to liquid is 1∶20,the ultrasonic power is 300 W,the microwave power is 310 W,and the ultrasonic microwave time is 120 s.Under these conditions,the extraction yield is 3.99%,which is higher than 2.82%of the direct hydrodistillation.The contents of D-limonene and lauraldehyde in essential oil that was extracted by the ultrasonic-microwave assisted extraction were decreased,whileα-pinene,linalool,α-terpineol,decyl aldehyde and(Z)-caryophyllene were increased.The results of biological activity study showed that the scavenging rate of DPPH by ultrasonic-microwave assisted hydrodistillation was significantly increased,but the effect on inhibition of E.coli had no significant difference.All results indicated that ultrasonic-microwave assisted method significantly increased extraction yield of essential peel oil and improved the antioxidant activity of essential oil.