The analysis of simultaneous clove/oregano and clove/thyme supercritical extraction

Extraction of Active Compounds from Mixtures of Hemp (Cannabis sativa) with Plants of the Zingiberaceae Family

Hemp is probably one of the most studied plants for its health-promoting properties, with countless documented and patented extraction methods, but literature is scarce on the simultaneous extraction of mixture of raw materials. Hemp, along with other plant materials, could represent a potentially highly valuable source material with resulting reciprocal effects. In this study, hemp (Cannabis sativa) and three members of the Zingiberaceae family, ginger (Zingiber officinale), turmeric (Curcuma longa), and cardamom (Elettaria cardamomum), were extracted simultaneously, and their bioactive component values were investigated. Two extraction methods were used, namely ultrasound-assisted extraction with ethanol and supercritical fluid extraction with carbon dioxide. First, extracts were obtained from separate plant materials. Then, hemp was extracted in combination with ginger, turmeric, and cardamom in a 1:1 ratio. The extracts obtained were evaluated for their antioxidant activity and total phenolic content using UV/VIS spectrophotometry; cannabinoid content, 6-gingerol, and 6-shogaol were measured using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS); volatile components such as 1,8-cineole, alpha-terpinyl acetate, linalool, and aR-turmerone were measured using gas chromatography with mass spectrometry (GC/MS).

Simultaneous determination of carvacrol and thymol in bee pollen by using a simple and efficient solvent extraction method and gas chromatography-mass spectrometry

A novel method is proposed to determine residues of carvacrol and thymol in bee pollen by means of gas chromatography coupled to mass spectrometry. This is an efficient and simple sample treatment (with average analyte recoveries between 90% and 104%) involving solvent extraction with hexane followed by evaporation. There is no need for any additional clean-up step, as the matrix did not affect determination of mass spectrometry for either compound. The chromatographic conditions are also optimized: a ZB-WAX column is employed, helium is the carrier gas at a flow rate of 1.1 mL/min, and a temperature program is included, allowing baseline separation of both compounds in less than 21 min. The method is fully validated in terms of selectivity, limits of detection and quantification, matrix effect, linearity, precision and trueness. Results show that not only is it selective, but that it also displays a wide linearity range (limit of quantification-1000 μg/kg), good precision (relative standard deviation values lower than 8%) and sensitivity (limits of detection and quantification lower than 15 μg/kg). Finally, several bee pollen samples are analysed, and thymol and carvacrol residues are found at low concentrations (limit of quantification-57 μg/kg) in some cases.

Extraction of α-humulene-enriched oil from clove using ultrasound-assisted supercritical carbon dioxide extraction and studies of its fictitious solubility

Clove buds are used as a spice and food flavoring. In this study, clove oil and α-humulene was extracted from cloves using supercritical carbon dioxide extraction with and without ultrasound assistance (USC-CO2 and SC-CO2, respectively) at different temperatures (32-50°C) and pressures (9.0-25.0MPa). The results of these extractions were compared with those of heat reflux extraction and steam distillation methods conducted in parallel. The extracts obtained using these four techniques were analyzed using gas chromatography and gas chromatography/mass spectrometry (GC/MS). The results demonstrated that the USC-CO2 extraction procedure may extract clove oil and α-humulene from clove buds with better yields and shorter extraction times than conventional extraction techniques while utilizing less severe operating parameters. Furthermore, the experimental fictitious solubility data obtained using the dynamic method were well correlated with density-based models, including the Chrastil model, the Bartle model and the Kumar and Johnston model.

Extraction of thymol from different varieties of thyme plants using green solvents

BACKGROUND

Thymol (2-isopropyl-5-methylphenol) is the main monoterpene phenol found in thyme essential oil. This compound has revealed several biological properties, including antibacterial, anti-inflammatory and antioxidant activities. In this work, a comparison was made between the performance of different green solvents (ethanol, limonene and ethyl lactate), by pressurized liquid extraction (PLE) and supercritical fluid extraction (SFE) at different conditions, to extract thymol from three different varieties of thyme (Thymus vulgaris, Thymus zygis and Thymus citriodorus). Additionally, new solubility data of thymol in limonene and ethanol at ambient pressure and temperatures in the range 30-43 °C are reported.

RESULTS

The highest thymol recoveries were attained with T. vulgaris (7-11 mg g(-1)). No thymol could be quantified in the PLE samples of T. citriodorus. The highest concentrations of thymol in the extracts were obtained with limonene. Thymol is very soluble in both solvents, particularly in ethanol (∼900 mg g(-1) at ∼40 °C), and is the main compound (in terms of peak area) present in the essential oil extracts obtained.

CONCLUSION

The three solvents show good capacity to extract thymol from T. vulgaris and T. zygis by PLE. Although PLE proved to be a suitable technology to extract thymol from thyme plants, the highest concentrations of thymol were obtained by SFE with supercritical CO2 .