abstract
The supercritical fluid extraction of grape seed (Vitis vinifera L) oil using carbon dioxide has been carried out at constant temperature (313.15 K) and solvent flow rate (1.7 x 10(-4) kg s(-1)), at 160, 180 and 200 bar, using both untreated and enzymatically pre-treated seeds. The pre-treatment of triturated seeds has been performed with a cell wall degrading enzyme cocktail containing cellulase, protease, xylanase, and pectinase, in order to enlarge the broken/intact cells ratio, thus increasing oil availability. The maximum extraction yield obtained was 16.5%, which is 44% higher than the 11.5% yield obtained with untreated seeds. The cumulative extraction curves measured show two characteristic periods: a first linear part where the majority of the oil is obtained, and a second asymptotic branch which contributes with only 3-8% to the total oil removed. As pressure rises, the mass Of CO(2) needed to reach a definite extraction yield decreases and the linear part of the extraction curves of treated and untreated seed approach themselves. (C) 2008 Elsevier B.V. All rights reserved.
keywords
CARBON-DIOXIDE; VEGETABLE-OILS; MASS-TRANSFER; CO2; SOLUBILITY; RECOVERY
subject category
Chemistry; Engineering
authors
Passos, CP; Silva, RM; Da Silva, FA; Coimbra, MA; Silva, CM
our authors
Groups
G3 - Electrochemical Materials, Interfaces and Coatings
G4 - Renewable Materials and Circular Economy
acknowledgements
The authors gratefully acknowledge Eng. A. Dias Cardoso from Caves Messias, Mealhada, Portugal, for the raw material provided. This work was supported by the Research Unit 62/94 QOPNA, and project POCTI/EQU/47533/2002. Claudia Passos was supported by a Ph.D. grant by FCT, SFRH/BD/19072/2004.