Kinetics of supercritical carbon dioxide extraction of borage and evening primrose seed oil

Petra Kotnik (Author), Mojca Škerget (Author), Željko Knez (Author)

Abstract

In the present work, high-pressure extraction of borage (Borago officinalis L.) and evening primrose (Oenothera biennis L.) seed oil, containing the valuable -linolenic acid (GLA), has been investigated. Extraction was performed with supercritical carbon dioxide on a semi-continuous flow apparatus at pressures of 200 and 300 bar, and at temperatures of 40 and 60 °C. A constant flow rate of carbon dioxide in the range from 0.17 to 0.20 kgžhwas maintained during extraction. The extraction yields obtained using dense CO2 were similar to those obtained with conventional extraction using hexane as solvent. The composition of extracted crude oil was determined by GCanalysis. The best results were obtained at 300 bar and 40 °C for both seed types extracted, where the quality of oil was highest with regard to GLA content. The evening primrose seed oil extracted with supercritical fluid extraction was particularly rich in unsaturated fatty acidsČ up to 89.7 wt-% of total free fatty acids in the oil. The dynamic behavior of the extraction runs was analyzed using two mathematical models for describing the constant rate period and the subsequent falling rate period. Based on the experimental data, external mass transfer coefficients, diffusion coefficients and diffusivity in solid phase were estimated. Results showed good agreement between calculated and experimental data.

Keywords

visokotlačna tehnologija;superkritični CO2;ekstrakcija olja semen;svetlin;boreč;proste maščobne kisline;kinetika;modeliranje;chemical processing;high pressure technology;supecritical CO2;seed oil extraction;evening primrose;borage;free fatty acids;kinetics;modeling;

Data

Language:	English
Year of publishing:	2006
Typology:	1.01 - Original Scientific Article
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
UDC:	66.061-987
COBISS:	10617878
ISSN:	1438-7697
Views:	1695
Downloads:	96
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary keywords:	visokotlačna tehnologija;superkritični CO2;ekstrakcija olja semen;svetlin;boreč;proste maščobne kisline;kinetika;modeliranje;
URN:	URN:SI:UM:
Pages:	str. 589-576
Volume:	ǂVol. ǂ108
Issue:	ǂiss. ǂ7
Chronology:	2006
ID:	8717109