title: [Check valve and non-oxygen microwave assisted extraction of Chinese herbs: study of a novel technique for extraction of essential oils].
abstract: OBJECTIVE
  A novel green extraction technique of check valve & non-oxygen microwave assisted extraction (CVNO-MAE) for essential oils extraction was established. CVNO-MAE is a combination of microwave heating, vacuum pump and check valve, performed at anaerobic environment without added any solvent or water.
  
  
  METHODS
  CVNO-MAE has been compared with a conventional technique, solvent free microwave extraction (SFME), for the extraction of essential oils from two Chinese herbs: Curcuma phaeocaulis and Mentha haplocalyx.
  
  
  RESULTS
  GC-MS analyses of the oils revealed the presence of 36 and 37 compounds in the essential oils of C. phaeocaulis and M. haplocalyx, respectively. There was an obvious difference in the quality of essential oils obtained by the two kinds of extraction methods. The CVNO-MAE method yielded an essential oil of C. phaeocaulis with lower amounts of oxygenated compounds (45.53%) than SFME (62.38%). Higher amounts of oxygenated compounds (89.57%) were present in the M. haplocalyx essential oil of SFME in comparison with CVNO-MAE (82.74%).
  
  
  CONCLUSIONS
  CVNO-MAE is a fast low temperature extraction method carried in under pressure, appears as a good alternative for the extraction of essential oils from Chinese herbs and a green technology.
authors: College of Chemical and Chemical Engineering of Chongqing University, Chongqing 400030, China. zxbygl@yahoo.com.cn
authors: Xiaobing
authors: X
authors: Zou
authors: Jin
authors: J
authors: Li
authors: Bin
authors: B
authors: Ma
authors: Yanlin
authors: Y
authors: Yu
mesh_terms: D030024:Curcuma / Q000737:chemistry*; D055772:Green Chemistry Technology / Q000295:instrumentation / Q000379:methods*; D027541:Mentha / Q000737:chemistry*; D008872:Microwaves; D009822:Oils, Volatile / Q000032:analysis / Q000302:isolation & purification*; D010936:Plant Extracts / Q000032:analysis / Q000302:isolation & purification*; D010938:Plant Oils / Q000032:analysis / Q000302:isolation & purification*
chemical_list: D009822:Oils, Volatile; D010936:Plant Extracts; D010938:Plant Oils