Comparision of conventional and supercritical CO2-extracted rosehip oil

Abstract

Supercritical CO2 (SCO2) can be utilized to extract oils from a number of plant materials as a nontoxic alternative to hexane, and there is industrial interest in using SCO2 extraction to obtain high-quality oils for cosmetics and other high-value applications. A possible substrate is rosehip (Rosa aff. rubiginosa) seed. The scope of our work was to select SCO2 extraction conditions and to compare cold-pressed, hexane-extracted and SCO2-extracted rosehip oil. We used a fractional factorial experimental design with extraction temperature (T, 40-60 °C), extraction pressure (p, 300-500 bar) and dynamic extraction time (t, 90-270 min) as independent variables and yield and color as response variables. Samples of 100 g flaked rosehip seeds were extracted with 21 g CO2/min, following a static extraction (15 min adjustment) period. Resulting data were analyzed using response surface methodology. Extracted oil (4.7-7.1% in our experimental region) increased slightly with p and more pronouncedly with T and specially t. On the other hand, the photometric color index was independent of t but worsened (increased) as a result of an increase in either p or specially T. We extracted five batches of 250 g seeds with 21 g CO2/min at 40 °C and 300 bar for 270 min and compared the oil with samples obtained by solvent extraction (a batch of 2.5 kg of laminated seeds was treated with 10 L hexane and rotaevaporated until there was virtually no residual hexane) and cold pressing, by determining color, fatty acid composition, iodine index and saponification index. It was concluded that SCO2 allows an almost complete recovery of rosehip oil (6.5% yield), which is of a better quality than the oil extracted with hexane. Yield was higher than it was when using a cold-pressing process (5.0% yield)

Extraction of oil and minor lipids from cold-press rapeseed cake with supercritical CO2

“…Consequently, SC-CO 2 extracted rapessed oil had a 11.5 ratio of unsaturated-tosaturated fatty acids, and a 3.68 ratio of polyunsaturated-to-saturated fatty acids. Very little difference in fatty acid composition was found between rapeseed oil extracted with SC-CO 2 and using hexane (except in the composition of fatty acids C18:0, C18:1, n9 trans, C18:1 n9 cis, C18:2), suggesting that the fatty acid content does not depend on extraction method (del Valle et al, 2000). Several works have reached a similar conclusion, including the classical one of Friedrich and List (1982) for soybean oil.…”

Contributions to supercritical extraction of vegetable substrates in Latin America

“…Most simple systems are devoid of mechanical means for solvent pressuring and pumping and include the batch extractor of del Valle and Aguilera (1989); the high-pressure N 2 pumping system of Sargenti and Lanças (1994) or thermal pumping system of Yépez, Espinosa, Lopez, and Bolañ os (2002), who used a small extraction vessel in combination with a larger vessel (500-1100 or 1300 cm 3 -capacity, respectively) to achieve a desirable combination of high-pressure and limited temperature by, e.g., heating a batch of liquid CO 2 (Yépez et al, 2002); and the liquid CO 2 extraction system of Sousa et al (2002), who used as the solvent liquid CO 2 at room temperature, at its saturation pressure of %67 bar, from a gas cylinder fitted with a siphoning tube. Small commercial systems including Hewlett-PackardÕs 7680T unit of Cassel et al (2000); Applied SeparationsÕ Speed SFE unit of Canela et al (2002) and Rodrigues, Rosa, et al (2003), and the modified Thar DesignsÕ SFE-1L unit of del Valle, Bello, Thiel, Allen, and Chordia (2000), del Valle, Jiménez, and de la Fuente (2003), del Valle et al (in press), del Valle, Rivera, Teuber, and Palma (2003), and Uquiche et al (2004) which are characterized by the use of air ovens for heating, are used mostly but not solely for analytical purposes. Homemade onepass, screening systems use gas booster pumps (Carlson, Machado, Spricigo, Pereira, & Bolzan, 2001), standard HPLC pumps (Canela et al, 2002;Martı nez et al, 2003;Rodrigues, Rosa, et al, 2003;Rodrigues et al, 2002;Spricigo, Pinto, Bolzan, & Novais, 1999;Yoda et al, 2003;Zancan et al, 2002), or syringe pumps (Rodrigues, Caramão, dos Santos, Dariva, & Oliveira, 2003) for solvent compression; relatively large cells (200-400 cm 3 ) for extraction, which are immersed in a water bath, or equipped with heating jackets or electrical heating tapes for temperature adjustment; and empty glass flasks or columns with adsorbent materials for the recovery of dissolved solutes (the loaded supercritical phase is expanded to atmospheric pressure in a single step).…”

“…Homemade onepass, screening systems use gas booster pumps (Carlson, Machado, Spricigo, Pereira, & Bolzan, 2001), standard HPLC pumps (Canela et al, 2002;Martı nez et al, 2003;Rodrigues, Rosa, et al, 2003;Rodrigues et al, 2002;Spricigo, Pinto, Bolzan, & Novais, 1999;Yoda et al, 2003;Zancan et al, 2002), or syringe pumps (Rodrigues, Caramão, dos Santos, Dariva, & Oliveira, 2003) for solvent compression; relatively large cells (200-400 cm 3 ) for extraction, which are immersed in a water bath, or equipped with heating jackets or electrical heating tapes for temperature adjustment; and empty glass flasks or columns with adsorbent materials for the recovery of dissolved solutes (the loaded supercritical phase is expanded to atmospheric pressure in a single step). Equivalent commercial systems included the modified Thar DesignsÕ SFE 1L (del Valle, Bello, et al, 2000;del Valle, Jiménez, & de la Fuente, 2003;del Valle et al, in press;del Valle, Rivera, et al, 2003;Uquiche et al, 2004), Autoclave EngineersÕ (Mohamed, Saldañ a, Mazzafera, Zetzl, & Brunner, 2002;Saldañ a, Mohamed, & Mazzafera, 2002), and TUHHÕs standardized low-cost batch SFEunit . In these systems high-pressure devices such as cyclone separators are typically used for the precipitation of dissolved solutes from the loaded supercritical phase.…”

Supercritical CO2 processing of pretreated rosehip seeds: effect of process scale on oil extraction kinetics

“…Extraction with conventional organic solvents produces lowquality oil that requires extensive refining, whereas expression is appropriate only for seeds containing ≥20% oil [1]. Previous work on SC-CO 2 extraction of oil-containing seeds has been reviewed recently [2]. An interesting substrate for SC-CO 2 extraction is rosehip (Rosa aff.…”

“…An interesting substrate for SC-CO 2 extraction is rosehip (Rosa aff. rubiginosa) seed, which is an inexpensive source of unsaturated fatty acid-rich oil used in cosmetics and other high-value applications [1][2][3][4][5][6].…”