resumo
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.
palavras-chave
CARBON-DIOXIDE; VEGETABLE-OILS; MASS-TRANSFER; CO2; SOLUBILITY; RECOVERY
categoria
Chemistry; Engineering
autores
Passos, CP; Silva, RM; Da Silva, FA; Coimbra, MA; Silva, CM
nossos autores
Carlos Manuel Silva
Professor associado
Francisco Avelino Silva Freitas
Professor Auxiliar
Rui Ramos Ferreira e Silva
Professor associadoGrupos
G3 - Materiais Eletroquímicos, Interfaces e Revestimentos
G4 - Materiais Renováveis e Economia Circular
agradecimentos
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.