离子液体超声-微波协同制取洋葱精油  

Preparation and extraction of onion essential oil by ionic liquid and ultrasound-microwave-assisted method

作　　者：曹红[1] 段海燕[1] 李春[1,2] 辛娜[1] 李军[1] 李炳奇[1] 

机构地区：[1]石河子大学化学化工学院,新疆兵团化工绿色过程重点实验室-省部共建国家重点实验室培育基地,新疆石河子832003 [2]北京理工大学生命学院,北京100081

出　　处：《化工学报》2012年第3期826-833,共8页CIESC Journal

基　　金：石河子大学科学研究发展计划“自然科学与技术创新”项目(ZRKX2008004)~~

摘　　要：以离子液体[BMIM]PF6作为生物催化介质,结果显示洋葱蒜氨酸酶在含25%[BMIM]PF6催化体系中的活性比在纯缓冲液介质中明显要高,对高温变性作用的抵抗能力也相应增强,但若离子液体浓度过高会对酶催化作用的发挥产生阻碍。以洋葱蒜氨酸为底物,测得离子液体[BMIM]PF6/缓冲液两相体系中蒜氨酸酶的米氏常数为0.591mmol·L-1,最大反应速率为0.316mmol·L-1·min-1,Vmax/Km约为缓冲液单相体系中的两倍。实验还尝试发挥疏水性离子液体[BMIM]PF6作为生物催化介质和萃取剂的双重功能,并将其与超声-微波协同萃取技术相结合应用于洋葱精油制取的酶解和萃取过程,明显提高了酶解效率和精油得率,将制得的精油经GC-MS分析,共鉴定出22种物质,其中19种为含硫化合物。To improve enzyme catalytic efficiency,the ionic liquid/buffer biphasic system was used as bio-catalytic medium in catalytic hydrolysis of alliin to the sulfur-containing compounds by alliinase.The results showed that the enzyme activity was higher for 25% PF6/ buffer biphasic system than for pure buffer system but inhibited markedly by excess amount of PF6,and the thermal stability of the enzyme was enhanced.Using natural alliin as substrate,the Km of 0.591 mmol·L-1 and the Vmax of 0.316 mmol·L-1·min-1 were obtained for the enzyme catalytic reaction in PF6/buffer biphasic system,and the Vmax/Km ratio was about 2 fold of buffer monophasic system.In addition,in order to rising yield of essential oil,a combination technique of ionic liquid PF6,as bio-catalytic medium and extraction agent,and ultrasound-microwave-assisted was used for preparation and extraction of onion essential oil.The optimized conditions established were as follows：PF6 concentration 20%（vol）,enzymatic time 2 h,ratio of raw material to liquid 1∶1.5,extraction temperature and time 25℃ and 50 s,and ultrasound-microwave power 150 W.Total 22 substances were identified in the onion essential oil prepared from fresh onion and 19 kinds of them sulfur-containing compounds by GC-MS analysis.

关 键 词：离子液体 [BMIM]PF6 超声-微波 蒜氨酸酶 洋葱精油 

分 类 号：O643[理学—物理化学] Q55[理学—化学]