The apparent solubility controls the initial stage of supercritical fluid extraction of natural products, which is most im portant for the process economics. Based on the literature, data on CO 2 apparent solubility of volatile substances from different matrices as leaves, flowers, rhizomes and seeds were collected and compared with their thermodynamic solu bility. The adsorption isotherm derived by del Valle and Urrego as a modification of the isotherm proposed by Perrut et al. is universal enough to interpret these data as well as the apparent solubility of vegetable oils from seeds, for which it was originally proposed. When the apparent solubility of minor extract components in CO 2 is compared with their thermodynamic solubility, their fraction in the extracted mixture should be taken into account.
P. T. V. Rosa and M. A. A. Meireles, “Rapid Estimation of the Manufacturing Cost of Extracts Obtained by Supercritical Fluid Extraction,” Journal of Food Engineering, Vol. 67, No. 1-2, 2005, pp. 235-240. doi:10.1016/j.jfoodeng.2004.05.064
H. Sovová, J. Ku?era and J. Je?, “Rate of the Vegetable Oil Extraction with Supercritical CO2-II. Extraction of Grape Oil,” Chemical Engineering Science, Vol. 49, No. 3, 1994, pp. 415-420. doi:10.1016/0009-2509(94)87013-6
V. M. Rodrigues, E. M. B. D. Sousa, A. R. Monteiro, O. Chiavone-Filho, M. O. M. Marques and M. A. M. Meireles, “Determination of the Solubility of Extracts from Vegetable Raw Material in Pressurized CO2: A Pseudo-Ternary Mixture Formed by Cellulosic Structure+Solute+Solvent,” Journal of Supercritical Fluids, Vol. 22, No. 1, 2002, pp. 21-36. doi:10.1016/S0896-8446(01)00108-5
H. Sovová, R. P. Stateva and A. A. Galushko, “Essential Oils from Seeds: Solubility of Limonene in Supercritical CO2 and How It Is Affected by Fatty Oil,” Journal of Supercritical Fluids, Vol. 20, No. 2, 2001, pp. 113-129. doi:10.1016/S0896-8446(01)00059-6
J. M. del Valle and F. A. Urrego, “Free Solute Content and Solute-Matrix Interactions Affect Apparent Solubility and Apparent Solute Content in Supercritical CO2 Extractions. A Hypothesis Paper,” Journal of Supercritical Fluids, Vol. 66, 2012, pp. 157-175. doi:10.1016/j.supflu.2011.10.006
J. M. del Valle and J. M. Aguilera, “An Improved Equation for Predicting the Solubility of Vegetable Oils in Supercritical CO2,” Industrial and Engineering Chemistry Research, Vol. 27, No. 8, 1988, pp. 1551-1553. doi:10.1021/ie00080a036
H. Sovová, M. Zarevúcka, M. Vacek and K. Stránsky, “Solubility of Two Vegetable Oils in Supercritical CO2,” Journal of Supercritical Fluids, Vol. 20, No. 1, 2001, pp. 15-28. doi:10.1016/S0896-8446(01)00057-2
J. M. del Valle, J. C. de la Fuente and E. Uquiche, “A Refined Equation for Predicting the Solubility of Vegetable Oils in High-Pressure CO2,” Journal of Supercritical Fluids, Vol. 67, 2012, pp. 60-70. doi:10.1016/j.supflu.2012.02.004
N. Bulley, M. Fattori, A. Meisen and L. Moyls, “Supercritical Fluid Extraction of Vegetable Oil Seeds,” Journal of the American Oil Chemists’ Society, Vol. 61, No. 8, 1984, pp. 1362-1365.
M. Perrut, J. Y. Clavier, M. Poletto and E. Reverchon, “Mathematical Modeling of Sunflower Seed Extraction by Supercritical CO2,” Industrial and Engineering Chem- istry Research, Vol. 36, No. 2, 1997, pp. 430-435. doi:10.1021/ie960354s
H. Sovová, “Mathematical Model for Supercritical Fluid Extraction of Natural Products and Extraction Curve Evaluation,” Journal of Supercritical Fluids, Vol. 33, No. 1, 2005, pp. 35-52. doi:10.1016/j.supflu.2004.03.005
M. Richter and H. Sovová, “The Solubility of Two Monoterpenes in Supercritical Carbon Dioxide,” Fluid Phase Equilibria, Vol. 85, 1993, pp. 285-300. doi:10.1016/0378-3812(93)80020-N
E. M. Z. Michielin, S. R. Rosso, E. Franceschi, G. R. Borges, M. L. Corazza, J. V. Oliveira and S. R. S. Ferreira, “High-Pressure Phase Equilibrium Data for Systems with Carbon Dioxide, α-Humulene and Trans-Caryophyllene,” Journal of Chemical Thermodynamics, Vol. 41, No. 1, 2009, pp. 130-137. doi:10.1016/j.jct.2008.07.006
E. Franceschi, M. B. Grings, C. D. Frizzo, J. V. Oliveira and C. Dariva, “Phase Behavior of Lemon and Bergamot Peel Oils in Supercritical CO2,” Fluid Phase Equilibria, Vol. 226, 2004, pp. 1-8. doi:10.1016/j.fluid.2004.06.041
A. T. Souza, M. L. Corazza, L. Cardozo-Filho, R. Guirardello and M. A. A. Meireles, “Phase Equilibrium Measurements for the System Clove (Eugenia caryophyllus) Oil + CO2,” Journal of Chemical Engineering Data, Vol. 49, No. 2, 2004, pp. 352-356. doi:10.1021/je034190f
T. M. Takeuchi, P. F. Leal, R. Favareto, L. Cardozo-Filho, M. L. Corazza, P. T. V. Rosa and M. A. A. Meireles, “Study of the Phase Equilibrium Formed inside the Flash Tank Used at the Separation Step of a Supercritical Fluid Extraction Unit,” Journal of Supercritical Fluids, Vol. 43, No. 3, 2008, pp. 447-459. doi:10.1016/j.supflu.2007.08.002
L. S. Moura, M. L. Corazza, L. Cardozo-Filho and M. A. A. Meireles, “Phase Equilibrium Measurements for the System Fennel (Foeniculum vulgare) Extract + CO2,” Journal of Chemical Engineering Data, Vol. 50, No. 5, 2005, pp. 1657-1661. doi:10.1021/je050119t
N. P. Povh, M. O. M. Marques and M. A. A. Meireles, “Supercritical CO2 Extraction of Essential Oil and Oleoresin from Chamomile (Chamomilla recutita [L.] Rauschert),” Journal of Supercritical Fluids, Vol. 21, No. 3, 2001, pp. 245-256. doi:10.1016/S0896-8446(01)00096-1
P. Kotnik, M. ?kerget and ?. Knez, “Supercritical Fluid Extraction of Chamomile Flower Heads: Comparison with Conventional Extraction, Kinetics and Scale-U,” Journal of Supercritical Fluids, Vol. 43, No. 2, 2007, pp. 192-198. doi:10.1016/j.supflu.2007.02.005
J. M. Prado, G. H. C. Prado and M. A. A. Meireles, “Scale-up Study of Supercritical Fluid Extraction Process for Clove and Sugarcane Residue,” Journal of Supercritical Fluids, Vol. 56, No. 3, 2011, pp. 231-237. doi:10.1016/j.supflu.2010.10.036
S. Quispe-Condori, M. A. Foglio, P. T. V. Rosa and M. A. A. Meireles, “Obtaining β-Caryophyllene from Cordia verbenacea de Candolle by Supercritical Fluid Extraction,” Journal of Supercritical Fluids, Vol. 46, No. 1, 2008, pp. 27-32. doi:10.1016/j.supflu.2008.02.015
J. Martínez, A. R. Monteiro, P. T. V. Rosa, M. O. M. Marques and M. A. A. Meireles, “Multicomponent Model to Describe Extraction of Ginger Oleoresin with Supercritical Carbon Dioxide,” Industrial and Engineering Chemistry Research, Vol. 42, No. 5, 2003, pp. 1057-1063. doi:10.1021/ie020694f
A. Berna, A. Tárrega, M. Blasco and S. Subirats, “Supercritical CO2 Extraction of Essential Oil from Orange Peel; Effect of the Height of the Bed,” Journal of Supercritical Fluids, Vol. 18, No. 3, 2000, pp. 227-237. doi:10.1016/S0896-8446(00)00082-6
B. C. Roy, M. Goto, A. Kodama and T. Hirose, “Supercritical CO2 Extraction of Essential Oils and Cuticular Waxes from Peppermint Leaves,” Journal of Chemical Technology and Biotechnology, Vol. 67, No. 1, 1996, pp. 21-26. doi:10.1002/(SICI)1097-4660(199609)67:1 3.0.CO;2-0
S. Aleksovski, H. Sovova, F. A. Poposka, S. Kulevanova and M. Ristic, “Comparison of Essential Oils Obtained from Mentha pipperita L. Using Supercritical Carbon Dioxide Extraction and Hydrodistillation,” Acta Pharmaceutica, Vol. 49, No. 1, 1999, pp. 51-57.
T. Hatami, S. B. Glisic and A. M. Orlovic, “Modelling and Optimization of Supercritical CO2 Extraction of St. John’s Wort (Hypericum perforatum L.) Using Genetic Algorithm,” Journal of Supercritical Fluids, Vol. 62, 2012, pp. 102-108. doi:10.1016/j.supflu.2011.12.001
M. Goto, M. Sato and T. Hirose, “Extraction of Peppermint Oil by Supercritical Carbon Dioxide,” Journal of Chemical Engineering (Japan), Vol. 26, No. 4, 1993, pp. 401-407. doi:10.1252/jcej.26.401
H. Sovová, R. P. Stateva and A. A. Galushko, “Essential Oils from Seeds: Solubility of Limonene in Supercritical CO2 and How It Is Affected by Fatty Oil,” Journal of Supercritical Fluids, Vol. 20, No. 2, 2001, pp. 113-129. doi:10.1016/S0896-8446(01)00059-6
B. Damjanovi?, ?. Lepojevi?, V. ?ivkovi? and A. Toli?, “Extraction of Fennel (Foeniculum vulgare Mill.) Seeds with Supercritical CO2: Comparison with Hydrodistillation,” Food Chemistry, Vol. 92, No. 1, 2005, pp. 143-149. doi:10.1016/j.foodchem.2004.07.019
S. Machmudah, A. Sulaswatty, M. Sasaki, M. Goto and T. Hirose, “Supercritical CO2 Extraction of Nutmeg Oil: Experiments and Modeling,” Journal of Supercritical Fluids, Vol. 39, No. 1, 2006, pp. 30-39. doi:10.1016/j.supflu.2006.01.007
M. D. A. Saldana, R. S. Mohamed, M. G. Baer and P. Mazzafera, “Extraction of Purine Alkaloids from Maté (Ilex paraguariensis) Using Supercritical CO2,” Journal of Agricultural and Food Chemistry, Vol. 47, No. 9, 1999, pp. 3804-3808. doi:10.1021/jf981369z
Z. Shen, M. V. Palmer, S. S. T. Ting and R. J. Fairclough, “Pilot Scale Extraction of Rice Bran Oil with Dense Carbon Dioxide,” Journal of Agricultural and Food Chemistry, Vol. 44, No. 10, 1996, pp. 3033-3009. doi:10.1021/jf950761z
M. C. Esmelindro, G. Toniazzo, D. Lopes, D. Oliveira and C. Dariva, “Effects of Processing Conditions on the Chemical Distribution of Mate Tea Leaves Extracts Obtained from CO2 Extraction at High Pressures,” Journal of Food Engineering, Vol. 70, No. 4, 2005, pp. 588-592. doi:10.1016/j.jfoodeng.2004.07.024
J. M. del Valle, M. Jiménez and J. C. de la Fuente, “Extraction Kinetics of Pre-Pelletized Jalapeno Peppers with Supercritical CO2,” Journal of Supercritical Fluids, Vol. 25, No. 1, 2003, pp. 33-44. doi:10.1016/S0896-8446(02)00090-6
O. Elizalde-Solis and L. A. Galicia-Luna, “New Apparatus for Solubility Measurements of Solids in Carbon Dioxide,” Industrial and Engineering Chemistry Research, Vol. 50, No. 1, 2011, pp. 207-212. doi:10.1021/ie1009537