Evaluation and mathematical modeling of processing variables for a supercritical fluid extraction of aromatic compounds from Anethum graveolens

The aim of this study is to identify the extraction conditions, using supercritical carbon dioxide as solvent, that maximize the yield of volatile extract from the seeds of Anethum graveolens L. by the use of the response surface method, where the variables pressure, temperature and flow rate of supercritical CO2 were investigated. A 23 factorial design combined with response surface methodology was used in order to achieve the goal. The best set of experimental conditions was determined to be P=100 bar, T=35 degrees C and solvent flow rate = 1000 g/h. The mathematical modeling of the extraction curve was performed under the best experimental conditions, and the olfactory profile of the extract and its antimicrobial activity were compared with the oil obtained from hydrodistillation. The gas chromatography analysis (GC) identified dillapiole, carvone and its isomers to be major compounds. The olfactory profile of A. graveolens extracts obtained was determined by gas chromatography-olfactometry (GC-O), and the most often identified aroma was cheese/bacon for the hydrodistillation oil, whereas in the supercritical extract, the most often identified aroma was burning bush. (C) 2016 Elsevier B.V. All rights reserved.