Comparison of microwave-assisted hydrodistillation withthe traditional hydrodistillation method in the extractionof essential oils from Thymus vulgaris L

Mohammad-Taghi Golmakani; Karamatollah Rezaei

doi:10.1016/j.foodchem.2007.12.084

Comparison of microwave-assisted hydrodistillation withthe traditional hydrodistillation method in the extractionof essential oils from Thymus vulgaris L

Food Chem. 2008 Aug 15;109(4):925-30. doi: 10.1016/j.foodchem.2007.12.084. Epub 2008 Jan 26.

Authors

Mohammad-Taghi Golmakani¹, Karamatollah Rezaei²

Affiliations

¹ Department of Food Science and Engineering, Faculty of Biosystem Engineering, The University of Tehran, P.O. Box 31587-77871, Karaj, Iran.
² Department of Food Science and Engineering, Faculty of Biosystem Engineering, The University of Tehran, P.O. Box 31587-77871, Karaj, Iran. Electronic address: krezaee@ut.ac.ir.

PMID: 26050009
DOI: 10.1016/j.foodchem.2007.12.084

Abstract

Microwave-assisted hydrodistillation (MAHD) is an advanced hydrodistillation (HD) technique utilizing a microwave oven in the extraction process. MAHD of essential oils from the aerial parts (tops) of Thymus vulgaris L. (common thyme) was studied and the results were compared with those of the conventional HD in terms of extraction time, extraction yield/efficiency, chemical composition, quality of the essential oils and cost of the operation. MAHD was superior in terms of saving energy and extraction time (75min, compared to 4h in HD). Scanning electron microscopy (SEM) of thyme leaves undergone HD and MAHD provided evidences as to a sudden rupture of essential oil glands with MAHD. Gas chromatography-mass spectrometry analysis of the extracted essential oils indicated that the use of microwave irradiation did not adversely influence the composition of the essential oils. MAHD was found to be a green technology.

Keywords: Essential oil composition; Microwave assisted hydrodistillation; Scanning electron microscopy; Thymus vulgaris L..