Extraction of Victoria and Red Globe grape seed oils using supercritical carbon dioxide with and without ethanol.

摘要

Supercritical fluid extraction (SFE) of the oils of 2 varieties of grape seeds (Victoria and Red Globe) was performed in a flow apparatus at 40 degrees C and 250 bar. The effect of the solvent on the extraction yield was studied using CO2 and CO2 modified with ethanol, and the yield of extraction was compared with conventional extraction methods (Bligh and Dyer and Soxhlet using hexane). Supercritical (SC) CO2 + ethanol extracted higher lipid amounts from both varieties, compared with SC CO2 extraction. The comparison between SFE and conventional extraction methods showed that the highest extraction yield was obtained with SC CO2 + ethanol (10%, w/w) (14.7 and 11.8% for Red Globe and Victoria grape seeds, respectively), while pure SC CO2 afforded the lowest lipid yields. The fatty acid compositions of the oils obtained by SFE were analysed. Fractions containing higher proportions of PUFA were obtained at lower solvent/dry grape seed ratios, while fractions richer in SFA and MUFA were obtained at higher solvent/dry grape seed ratios. Results suggest the potential use of SC CO2 + ethanol as a solvent for grape seed oil extraction, showing a great advantage compared with conventional extraction methods.