Article

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

Journal of Supercritical Fluids

M. Moldão-Martins; António Manuel de Figueiredo ; Maria Gabriela da Silva Bernardo-Gil2000Elsevier

Key information

Authors:

M. Moldão-Martins; António Manuel de Figueiredo (António Manuel de Figueiredo Palavra); M. Luisa Beirão da Costa; Maria Gabriela da Silva Bernardo-Gil (Maria Gabriela da Silva Bernardo Gil)

Published in

August 2000

Abstract

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.

Publication details

Publisher

Elsevier

Title of the publication container

Journal of Supercritical Fluids

First page or article number

25

Last page

34

Volume

18

Issue

1

Fields of Science and Technology (FOS)

chemical-engineering - Chemical engineering

Publication language (ISO code)

eng - English

Rights type:

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