摘要
通过与普通加热萃取虎杖中白藜芦醇的产率进行对比 ,对密闭系统中微波辅助萃取的机理进行了探讨。结果表明 ,微波辅助萃取与普通加热萃取二者的活化能相差不大 ,分别为30.06和30.32kJ·mol-1。但微波辅助萃取的表观速率常数约是普通加热萃取的20倍。并且还利用电子扫描显微镜对样品微结构进行了观察 ,研究表明 ,细胞内极性成分如水吸收了微波能后压力迅速增加导致细胞结构的破坏是MAE快速高效的关键 ,由于细胞的破坏 ,萃取剂和萃取目标化合物更容易通过细胞壁 ,加速了扩散速度 ,进而加速了萃取速度。
The mechanism concerning the microwave_assisted extraction(MAE)of resveratrol in Huzhang sample under closed vessel condition was studied by comparison with that using the conventional reflux heating(RH)method.Experimental data show that the apparent activation energies for resveratrol obtained by MAE and RH were30.06and30.32kJ·mol -1 ,respectively,but the apparent rate constant of MAE was higher than that of RH by a factor of almost20.The microstructures of Huzhang before and after MAE,after microwave irradiation(MI)and MI followed by RH were scanned by the electron microscope.The results revealed that the increased efficiency and rate of MAE of resveratrol in Huzhang could be mainly attributed to the subsequent cell rupture resulting from the superheating effect of water within the cell during MI.The constituents,including Res,within the cell could then be easily diffused into the penetrated organic solvent.
出处
《分析测试学报》
CAS
CSCD
北大核心
2004年第5期12-16,20,共6页
Journal of Instrumental Analysis
基金
国家重点基础研究发展项目 (G2000026302)
关键词
微波辅助萃取
萃取机理
白藜芦醇
密闭系统
Microwave-assisted Extraction
Mechanism of Extraction
Resveratrol
Closed vessel condition
