Supercritical CO2 extraction of black poplar (Populus nigra L.) extract: Experimental data and fitting of kinetic parameters

摘要

The yields of extract obtained from black poplar seeds by supercritical fluid extraction are presented. The behavior of the kinetic curves and composition of the extracts in terms of fatty acids are also presented for different temperatures (40, 60 and 80 degrees C) and pressures (15, 20 and 25 MPa). The condition of 80 degrees C and 25 MPa, amongst those studied, yielded the highest yield (7.7 g extract/100 g dried black poplar seeds) and the highest content of polyunsaturated fatty acids in the extract (65.1%). In such condition, the extract was mostly composed by 28.3% of linoleic acid, 18.0% of gamma-linolenic acid and 10.9% of dihomogamma-linolenic acid. Furthermore, after fitting kinetic parameters for the extraction curves using the spline and Sovova's models, the extraction rates (17 x 10(-3) g/min) and the mass ratio of solute in the fluid phase for the constant extraction period (4.3 x 10(-3) g extract/g CO2) were larger when the extractions were performed at 80 degrees C and 25 MPa. At this temperature and pressure combination, the mass transfer coefficient for the solvent phase was equal to 208.1 x 10(-3)/min. (C) 2016 Elsevier B.V. All rights reserved.