Chemical Composition and Extraction Yield of the Extract of Origanum vulgare Obtained from Sub- and Supercritical CO₂

Abstract

In this work sub- and supercritical CO(2) were used to obtain extracts from two origanum samples, one commercial, and another cultivated under agronomic control. The experiments were performed in the temperature range of 293-313 K and from 100 to 200 bar in pressure, employing around 26 g of origanum samples. Results show that the commercial sample provides a higher yield of extract if compared to the other sample. It is also achieved that a raise in temperature at constant pressure leads to an increase in the extraction yield despite solvent density changes. Chemical analyses were carried out in a GC-MSD, allowing the identification of around 24 compounds by use of the library of spectra of the equipment and injection of some standard compounds for both commercial and cultivated origanum samples. It was also found that the distribution of chemical components as a function of extraction time differs appreciably between the origanum species. The chromatographic analysis permitted the identification of thymol and cis-sabinene hydrate as the most prominent compounds present in commercial oregano sample and carvacrol and cis-sabinene hydrate in the cultivated Origanum vulgare.

Determinação de óleos essenciais de alfavaca (Ocimum gratissimum L.), orégano (Origanum vulgare L.) e tomilho (Thymus vulgaris L.)

“…Neste mesmo sentido, Rodrigues (2002), Rodrigues et al (2004), Busatta et al (2007) e Busatta et al (2008), estudando o rendimento de óleo essencial em orégano, obtiveram valor médio de 1,2%, que também é superior ao detectado neste ensaio. Hudaib et al (2002) utilizaram as partes aéreas das plantas frescas de Thymus vulgaris L. (tomilho) e obtiveram rendimento de óleo de 0,15%, valor considerado inferior ao deste trabalho (0,64%) em relação às plantas frescas.…”

Chemical profile and antimicrobial activity of Boldo (Peumus boldus Molina) extracts obtained by compressed carbon dioxide extraction

“…In this work, the extracts of boldo had antimicrobial activity over Escherichia coli and Staphylococus aureus, but not against Pseudomonas aeruginosa. This fact might indicate that extraction method can affect the antimicrobial activity of the extracts, since depending on the extraction method employed, the distribution of compounds in the essential oil can vary greatly (Rodrigues et al, 2003(Rodrigues et al, , 2004.…”

“…The experiments were performed in a laboratoryscale unit, described in detail elsewhere (Rodrigues et al, 2003(Rodrigues et al, , 2004Mossi et al, 2004), which consists of a CO 2 (White Martins S.A., 99.9% in liquid phase) reservoir, two thermostatic baths, a syringe pump (ISCO 260D), a 100 cm 3 jacketed extraction Brazilian Journal of Chemical Engineering Vol. 25, No.…”

“…Extractions using supercritical carbon dioxide as solvent can be performed under mild conditions, thus reducing the risks of thermal degradation and the poor collection efficiencies of volatile analytes that can sometimes occur during the steam distillation or solvent extraction of essential oils and fragrance components (Sargenti and Lanças, 1997). Moreover, it is well known that extraction method may have a strong effect on both the qualitative and the quantitative chemical profiles of terpenic compounds found in the extracts of herbaceous matrices (Rodrigues et al, 2003(Rodrigues et al, , 2004.…”

Phytochemical profile, antioxidant and antimicrobial activity of extracts obtained from erva-mate (Ilex paraguariensis) fruit using compressed propane and supercritical CO2

“…With known values of pressure and temperature in the syringe pump reservoir, solvent densities were calculated and accordingly the mass of solvents charged into the extraction vessel. For more information on the methods used in the extraction process, the reader is addressed to the works of Jacques et al (2007a, b) and Rodrigues et al (2004).…”