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Extraction of thymol from different varieties of thyme plants using green solvents
Author(s) -
Villanueva Bermejo David,
Angelov Ivan,
Vicente Gonzalo,
Stateva Roumiana P,
Rodriguez GarcíaRisco Mónica,
Reglero Guillermo,
Ibañez Elena,
Fornari Tiziana
Publication year - 2015
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.7031
Subject(s) - thymol , thymus vulgaris , chemistry , essential oil , monoterpene , extraction (chemistry) , ethanol , limonene , supercritical fluid , supercritical fluid extraction , food science , chromatography , organic chemistry
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 CO 2 . © 2014 Society of Chemical Industry