Supercritical CO2 extraction of Thymus zygis L. subsp. sylvestris aroma

Agosto 2000

The supercritical fluid extraction (SFE) of aroma compounds from Thyme (Thymus zygis L. subsp. sylvestris) was studied. Extraction was conducted at different temperatures (300323 K) and pressures (820 MPa). The extraction time was varied between 40 and 100 min. The study was carried out according to the response surface methodology (RSM). The extracts were analyzed by gas chromatography (GC) and gas chromatographymass spectrometry (GC-MS). The yield and the composition of the extracts obtained by supercritical CO2 were compared with those obtained by steam distillation (SD). SFE produced higher extraction yields than SD. This may be explained by simultaneous extraction of both aroma and non aroma compounds of higher molecular weight. Higher yields were produced for the higher values of pressure (20 MPa) and extraction time (120 min). With respect to extract composition, the content of hydrocarbon monoterpenes was shown to be mainly related to the extraction temperature, higher values being produced between 308 and 310 K. Phenols, including thymol, the major component of T. zygis aroma, were also extracted at the higher tested levels of the parameters. The production of the terpenic alcohols (TA) was found to be mainly dependent on the extraction time. This study allows the conclusion that pressure is the most important extraction parameter.

Autores da comunidade :

• 

  A

  António Manuel de Figueiredo Palavra

  ist10657

• 

  M

  Maria Gabriela da Silva Bernardo Gil

  ist11061

  Afiliações e fontes

  IST > iBB

  Instituto de Bioengenharia e Biociências

  IST > CERENA

  Centro de Recursos Naturais e Ambiente

  IST > CEBQ

  Centro de Engenharia Biológica e Química

Elsevier

Journal of Supercritical Fluids

25

34

18

1

10.1016/S0896-8446(00)00047-4

chemical-engineering - Engenharia Química

eng - Inglês