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The efficient production of saponin-rich extracts is of increasing interest due to the bioactive properties that have being demonstrated for these compounds. However, saponins have a poor bioavailability. In this respect, the knowledge about the bioaccessibility of saponins as a first step before bioavailability has been scarcely explored. In this study, the production of ultrasound-assisted extracts of saponins from edible seeds (quinoa, soybean, red lentil, fenugreek and lupin) was carried out with ethanol, ethanol:water or water. Extraction yield, total saponin (TSC), fat and total phenolics content (TPC) were determined. Then, the bioaccessibility of saponins after the in vitro gastrointestinal digestion of the extracts was determined and the effect of TPC and fat in the extracts on bioaccessibility was evaluated. The highest saponin-rich extracts were obtained by ethanol, being fenugreek and red lentil the richest extracts (12% and 10%, respectively). Saponins from ethanol:water extracts displayed variable bioaccessibility (from 13% for fenugreek to 83% for lentil), but a bioaccessibility closer to 100% was reached for all ethanol extracts. Correlation studies showed that TPC of the extracts negatively affected the bioaccessibility of saponins, whereas fat of the extracts enhanced this parameter. As summary, ultrasound-assisted extraction is shown as an efficient method for obtaining saponin-rich extracts from edible seeds, being ethanol the most advantageous solvent due to the richness of saponins and the successful bioaccessibility from these extracts, likely caused by the co-extracted fat with ethanol. Regardless of the extracts, phenolic compounds or fat may hinder or enhance the bioaccessibility of saponins, respectively. Additionally, an adequate balance between saponins to lipids has shown to be relevant on such an effect., This work was supported by the Ministerio de Economía y Competitividad, Spain (AGL2016-76736-C3-1-R) and the Community of Madrid, Spain (ALIBIRD-CM S2013/ABI-2728). Joaquín Navarro del Hierro thanks the Ministerio de Educación, Cultura y Deporte for funding his research with a FPU predoctoral contract (FPU 15/04236). Teresa Herrera thanks the Community of Madrid for her contract (Fondo Social Europeo, Programa Operativo de Empleo Juvenil e Iniciativa de Empleo Juvenil YEI).

The digestion, absorption, uptake and bioavailability of a rosemary supercritical fluid extract encapsulated in oil in water emulsion were studied. Two emulsions with opposite surface charge were prepared, containing 7% canola oil, and either 2% lactoferrin or whey protein isolate. When absorption and uptake of carnosic acid and carnosol were followed on Caco-2 cell monolayers, there were no differences with protein type. However, when co-cultures of HT-29 MTX were employed, the presence of mucus caused a higher retention of carnosic acid in the apical layer for lactoferrin emulsions. The immune activity of the bioavailable fractions collected from cell absorption experiments was tested ex vivo on murine splenocytes. Although transport through the intestinal barrier models was low, the bioavailable fractions showed a significant effect on splenocytes proliferation. These results demonstrated the potential of using rosemary supercritical extract through protein stabilized oil in water emulsions, as a food with immunomodulatory functionality., This work was partly funded by the Natural Sciences and Engineering Council of Canada, through the Canada Research Chair program and the Spanish Ministry of Economy and Competitiveness (FORCANCER project, AGL2013- 48943-C2-1-R). EA work was supported by the Alfonso Martin Escudero Foundation, through a Post-Doctoral Fellowship.

In this work the fractionation of an ethanolic extract of Achillea millefolium L. (yarrow) using supercritical carbon dioxide anti-solvent technique was studied, with the target of increasing the concentration of phenolic compounds in the precipitated fraction. The effect of pressure on the selective precipitation was analyzed, together with the morphology and particle size distribution of the precipitates. In the range of pressures studied (10–20 MPa), up to a 3 fold increase of the total phenolic compound concentration was observed in the precipitates in comparison with the ethanolic yarrow extract. In addition, the selective fractionation of the main phenolic compounds identified in the extract (3,5-dicaffeoylquinic acid, a glycoside form of apigenin and luteolin, as well as the aglycones) was analyzed. Particle sizes around 250–330 μm were produced with a nozzle of 101.6 μm inner diameter, due to the formation of aggregates. In this respect, increasing pressure from 10 to 15 MPa resulted in smaller particles, while further pressure increasing had no significant effect on particle size decrease., The authors gratefully acknowledge the financial support from Ministerio de Economía y Competitividad of Spain (project AGL2013-48943-C2) and the Comunidad Autónoma de Madrid (ALIBIRD, project number S2013/ABI-2728).

The simultaneous fractionation and precipitation of an ethanolic extract of rosemary (Rosmarinus officinalis L.) using supercritical carbon dioxide anti-solvent technique was studied, with the target of separate in two different fractions the key antioxidants of rosemary (i.e. rosmarinic acid, carnosic acid and carnosol). The effect of pressure and temperature on the fractionation process was investigated, together with the morphology and particle size distribution of the precipitates. Additionally, the chemical composition of the oleoresins were analyzed and reported. In the range of pressures (9–20 MPa) and temperatures (313–333 K) used in this work, the precipitates presented a 2–3 fold enrichment of rosmarinic acid, while carnosic acid and carnosol were concentrated (2–3 fold enrichment) in the oleoresin fractions. Furthermore, in general, oleoresins presented higher antioxidant activity than precipitates. Particles produced with a nozzle of diameter 101.6 μm were smaller and more spherical with increasing pressure (mean value 4–10 μm at 20 MPa) and decreasing temperature., The authors gratefully acknowledge the financial support from Ministerio de Economía y Competitividad of Spain (Proyect AGL2016-76736-C3-1-R). Somaris E. Quintana is grateful for the funding provided by Gobernación de Bolivar and Fundación Ceiba, Colombia, in the project “Bolívar Gana con Ciencia”.

Supercritical carbon dioxide (SCCO) extraction is an innovative and efficient method to recover valued substances from vegetal materials. The diffusion behavior of the extract in the supercritical solvent is an important parameter to understand the mass transfer behavior of the process. In this work, experimental data from the literature were utilized to analyze the diffusivity of lipophilic chemically similar solutes in SCCO. Substances with similar chemical structure, molecular weight and volatility, have also very similar diffusion coefficients, which are mainly determined by temperature, pressure and, in turn, by the corresponding physicochemical properties of the supercritical solvent (density and viscosity). Based on this premise, general correlations were derived to represent the diffusion coefficient of volatile oils, fatty acids and its esters, and fixed oils (triglycerides) in SCCO as a function solely of pressure and temperature. The diffusion coefficients obtained were satisfactory compared with those calculated with theoretical and semi-empirical models from the literature, which require pure component parameters., López-Padilla A thanks to COLCIENCIAS (568–2012) and Medellin Mayor's Office (Sapiencia/Enlaza Mundos Program, 2013) for the Ph.D. fellowship. This work was financed thanks ALIBIRD, S2013/ABI-2728 (Comunidad de Madrid) project.

This paper reports experimental data to analyze the effect of different green cosolvents, namely ethyl lactate, ethyl acetate and ethanol, on the supercritical carbon dioxide (SCCO) extraction of caffeine from green tea leaves. The experiments were carried out in a pilot-scale plant using two different approaches: a static procedure in which the cosolvent was introduced in the extraction cell soaking the vegetal material and then SCCO was pumped, and a dynamic assay in which the cosolvent was pumped and mixed with SCCO before introduction into the extraction cell. The overall caffeine recovery from plant matrix was determined for all experiments at the same extraction conditions (30 MPa and 343 K). Additionally, the overall extraction curves of the static experiments were determined at the same process conditions, and the mass transfer model of Sovová was utilized to adjust the kinetic data and to determine the mass transfer coefficients. The highest caffeine yield was obtained with ethyl lactate in both static and dynamic extractions (13.0 and 14.2 mg/g of tea, respectively), followed by ethanol (10.8 mg/g with the static method and 8.8 mg/g with the dynamic method). The yield obtained with ethyl acetate in both extraction approaches was lower than 7 mg/g. These data reinforce previous results obtained by the authors regarding the competence of ethyl lactate in the extraction of caffeine from natural materials., D. Villanueva acknowledges the predoctoral contract (JAE) given by the Consejo Superior de Investigaciones Científicas (CSIC) of Spain. This work was financed thanks ALIBIRD, S2013/ABI-2728 (Comunidad de Madrid) project.

ALIBIRD, a test substance composed of oligosaccharides derived from lactulose, a hydrolysate of a whey protein concentrate, and a supercritical extract of rosemary (1:0.5:0.05), was prepared in the laboratory and evaluated for its safety as a multifunctional food additive. In oral toxicity studies (acute and 28 days repeated dose) using Wistar rats, ALIBIRD was administered in a single oral gavage dose of 2,000 mg/kg of body weight and resulted in no adverse events or mortality; a daily dose of 2,000 mg/kg of body weight for 28 days by gavage also resulted in no adverse effects or mortality. No abnormal clinical signs, behavioral changes, body weight changes, or changes in food and water consumption occurred in either study. There were no changes in hematological and serum chemistry values, organ weights, or gross or histological characteristics. Based on test results, it is concluded that ALIBIRD is well tolerated in rats at an acute and subchronic (28 days) dose of 2,000 mg/kg of body weight. Copyright ©, International Association for Food Protection.

5-Fluorouracil (5-FU) is the most used chemotherapeutic agent in colorectal cancer. However, resistance to this drug is relatively frequent, and new strategies to overcome it are urgently needed. The aim of this work was to determine the antitumor properties of a supercritical fluid rosemary extract (SFRE), alone and in combination with 5-FU, as a potential adjuvant therapy useful for colon cancer patients. This extract has been recognized as a healthy component by the European Food Safety Authority (EFSA). The effects of SFRE both alone and in combination with 5-FU were evaluated in different human colon cancer cells in terms of cell viability, cytotoxicity, and cell transformation. Additionally, colon cancer cells resistant to 5-FU were used to assay the effects of SFRE on drug resistance. Finally, qRT-PCR was performed to ascertain the mechanism by which SFRE potentiates the effect of 5-FU. Our results show that SFRE displays dose-dependent antitumor activities and exerts a synergistic effect in combination with 5-FU on colon cancer cells. Furthermore, SFRE sensitizes 5-FU-resistant cells to the therapeutic activity of this drug, constituting a beneficial agent against both 5-FU sensitive and resistant tumor cells. Gene expression analysis indicates that the enhancement of the effect of 5-FU by SFRE might be explained by the downregulation of TYMS and TK1, enzymes related to 5-FU resistance. © 2013 Elsevier Ltd. All rights reserved., This work has been supported by Spanish Ministry of Science and Innovation (Plan Nacional I+D+i AGL2010-21565, RyC 2008-03734), Comunidad de Madrid (ALIBIRD, S2009/AGR-1469), Fundación Mapfre, and European Union Structural Funds.

Supercritical fluid extraction (SFE) is an innovative, clean and environmental friendly technology with particular interest for the extraction of essential oil from plants and herbs. Supercritical CO 2 is selective, there is no associated waste treatment of a toxic solvent, and extraction times are moderate. Further, supercritical extracts were often recognized of superior quality when compared with those produced by hydro-distillation or liquid-solid extraction. This review provides a comprehensive and updated discussion of the developments and applications of SFE in the isolation of essential oils from plant matrices. SFE is normally performed with pure CO 2 or using a cosolvent; fractionation of the extract is commonly accomplished in order to isolate the volatile oil compounds from other co-extracted substances. In this review the effect of pressure, temperature and cosolvent on the extraction and fractionation procedure is discussed. Additionally, a comparison of the extraction yield and composition of the essential oil of several plants and herbs from Lamiaceae family, namely oregano, sage, thyme, rosemary, basil, marjoram and marigold, which were produced in our supercritical pilot-plant device, is presented and discussed. © 2012 Elsevier B.V., This work has been supported by project AGL2010-21565 (subprogram ALI) and project INNSAMED IPT-300000-2010-34 (subprogram INNPACTO) from Ministerio de Ciencia e Innovación (Spain) and Comunidad Autónoma de Madrid (project ALIBIRD-S2009/AGR-1469).

Production of prebiotic carbohydrates at competitive prices is a challenge nowadays since the well-established production processes involve many purification steps which are labour intensive and require important amounts of reagents and products thus increasing prebiotic's price. Several processes have been studied in our laboratory involving the use of Supercritical Fluid Technology to fractionate and purify carbohydrate solid mixtures. Research carried out at laboratory scale using theoretical mixtures (lactose/lactulose and galactose/tagatose), commercially available carbohydrate mixtures and carbohydrate mixtures produced by enzymatic transglycosylation and isomerized with complexating reagents demonstrated that purification of prebiotic carbohydrates was technically possible by supercritical fluid extraction. In the present work, the process optimized at laboratory scale to fractionate carbohydrate mixtures produced by enzymatic transglycosylation has been scaled-up to an industrial level and its economic feasibility has been simulated employing AspenONE ® V7.3 software to obtain consistent data supporting the interest of a potential investment for prebiotics production at large scale using supercritical fluids. © 2012 Elsevier B.V., This work has been financed by CSD2007-00063 FUN-CFOOD (Programa CONSOLIDER-INGENIO 2010) and Project ALIBIRD S2009/AGR-1469 (Community of Madrid) projects. F.M. thanks MEC and FECyT for a postdoctoral fellowship.

In this paper, the potential application of non-toxic agrochemical solvent—ethyl lactate, to recover α-tocopherol from olive oil is studied. The work is based on experimental and modeling studies of the liquid–liquid equilibria at ambient pressure of three model systems: (i) binary (olive oil + ethyl lactate), (ii) pseudo-binary (ethyl lactate + (olive oil containing 11.60 mass% of oleic acid)), (iii) ((ethyl lactate containing 2.80% of water) + olive oil), and (iv) ternary (α-tocopherol + olive oil + ethyl lactate). The favorable separation factors obtained reveal the strength and potential of ethyl lactate as a green solvent for the recovery.

Supercritical fluid chromatography (SFC) was employed to fractionate thyme (Thymus vulgaris L.) extracts, which were obtained by supercritical carbon dioxide extraction of thyme leaves. First, different supercritical extracts were produced at 313 K and at different pressures (15, 30 and 40 MPa). Thymol, a monocyclic terpenoid with recognized antiseptic, analgesic and anti-inflammatory properties, was identified and quantified in the different samples by GC-MS. Then, the supercritical extracts were fractionated by semi-preparative SFC, and different conditions such as pressure, temperature and amount of cosolvent (ethanol) employed were studied. Around a two fold increase of thymol was achieved at 15 MPa, 50 °C and 3% ethanol cosolvent, recovering 97% of the monocyclic terpenoid extracted. © 2010 Elsevier B.V. All rights reserved., The authors gratefully acknowledge the financial support from the Ministerio de Ciencia e Innovación (project 25506 FUN-C-FOOD) and Comunidad Autónoma de Madrid (ALIBIRD, project S-505/AGR-0153).

Chrastil (1982) [6] demonstrated that the solubility of a substance in a supercritical fluid (SCF) can be correlated with the density of the pure supercritical gas. Therefore, Chrastil's equation permits calculation of the supercritical phase composition of binary SCF + substance mixture based on the knowledge of the supercritical gas density and avoiding the use of equation of state based models. In this work, it is demonstrated that the supercritical fluid density also defines the liquid phase composition of binary systems; a density-dependent relationship is presented to calculate the solubility of supercritical gases in organic liquids. The isothermal solubility of several gases commonly employed in supercritical processing, such as carbon dioxide, methane, and ethane, in different organic liquids, including alkanes, alkenes, alcohols, acids, ketones, esters, terpenes and aromatic compounds, was successfully correlated as a function solely of the pure supercritical fluid density. As an application, pressure vs. composition phase diagrams of binary SCF + substance mixtures were obtained circumventing the use of equation of state models.

Prebiotic carbohydrates are defined as non-digestible carbohydrates that beneficially affect the host by selectively stimulating the growth and/or activity of a limited number of bacteria in the colon. The present study is focused on two prebiotic ketosugars: tagatose and lactulose, which are currently obtained by alkaline isomerization of their respective aldoses—galactose and lactose. It is a part of a broader research devoted to examining the possibility of complex solid carbohydrate mixtures fractionation using supercritical carbon dioxide and alcohol-type cosolvents. We report new experimental solubility data of tagatose, galactose, lactulose and lactose in supercritical carbon dioxide with ethanol:water (95:5, v/v) used as a cosolvent at T = (60 and 100) °C, P = (10–30) MPa and cosolvent content from 6 to 21% (w/w). The solubility measured was in the range (0.02–1.09) mg g −1 . Additionally, the experimental data was correlated using the Soave–Redlich–Kwong cubic equation of state with the modified Huron-Vidal second order (MHV2) mixing rule. The latter employs the mS-UNIFAC, which introduces two new groups in the original UNIFAC parameter matrix to represent the sugar molecules.

Supercritical carbon dioxide was used as an extractive solvent to remove free fatty acids from cold-pressed olive oil. Crude oil of different acidity content (from 0.5 to 4.0 wt%) was extracted in a packed column at 313 K and pressures of 180, 234 and 250 bar. The group contribution equation of state was employed to simulate the separation process, representing the oil as a simple pseudo-binary oleic acid + triolein mixture. Despite the simple representation of oil composition to simulate the deacidification process, a satisfactory agreement between the experimental and calculated yields and acidity of raffinates was obtained. The thermodynamic model was employed to study a continuous countercurrent multistage extraction process which yielded a raffinate having acidity lower than 0.7 wt%, when crude olive oil with different FFA content was processed.

A new application of the kinetics modeling for the optimal reutilization of an immobilized lipase from Pseudomonas cepacia in the ethanolysis of vegetable oils is presented. Two different rate expressions were explored to take into account the lipase inactivation. The methodology developed is based on the utilization of the pseudo reaction time that indicates how much longer the reaction mixture must remain in the reactor (actual reaction time) to achieve the conversion that would have been achieved if the enzyme had not been partially deactivated (pseudo reaction time). An initial batch of lipase was employed in 15 consecutive trials in order to quantitatively characterize the process over a range of lipase activity and to validate the ability of the methodology utilized to describe the kinetics of both ethanolysis and deactivation. Then, the model developed was employed to predict the time necessary to attain a desired conversion in subsequent reaction cycles in both, trials with the same batch of lipase with different degree of inactivation, and trials with a new batch of immobilized lipase with different specific activity. The reaction times predicted to attain a 38% disappearance of glyceryl ester bonds were experimentally verified by carrying out the corresponding ethanolysis reactions of 100 g of sunflower oil. The agreement between the desired and experimentally attained conversions achieved validates the methodology developed to estimate reaction time in lipase-catalyzed ethanolysis reactions.

This work explores the capabilities of UNIFAC-based models to predict the solubility of different solid solutes in subcritical water as a function of temperature. The original UNIFAC, its modified (Dortmund) version and the A-UNIFAC model, which explicitly includes association effects between groups, are applied to calculate the solubility of solid compounds in subcritical water in the temperature range 298–500 K. The comparison between the three models is carried out using polycyclic aromatic hydrocarbons (PAHs) as test substances and for which reliable physical properties and experimental solubility data are available in the literature. The results obtained indicate that modified UNIFAC (Dortmund) provides the best representation of the aromatic compounds’ solubility as a function of temperature. In addition, the application of the A-UNIFAC model confirms the hypothesis that a decrease in the level of association between the subcritical water molecules (in accordance with the dielectric constant decrease with temperature), greatly improves the solubility of hydrophobic organic compounds.

Nowadays consumers hold high standards for the foods they consume and they also demand for products that can provide added healthful benefits; two of these products with an observed prebiotic activity, tagatose and lactulose, are the core of our study. These two carbohydrates are ketoses and have important biological activities, such as the stimulation of the growth of beneficial microorganisms in the colon. They are currently produced by alkaline isomerization of the corresponding aldose, followed by several purification steps to remove carbohydrate by-products and the unreacted aldose (around 30%). In this work, the possibility of using supercritical fluid extraction (SFE) technology to fractionate complex carbohydrate mixtures is analyzed. The study is based on previous results obtained for the fractionation of solid binary carbohydrate mixtures such as lactulose–lactose and tagatose–galactose. The appropriate selection of the co-solvent employed, together with the most suitable extraction conditions (including temperature, pressure and co-solvent flow rate) allows the selective extraction of the prebiotic ketose with high selectivity and recovery. The fractionation by SFE of a complex commercial carbohydrate mixture, containing around 74 wt.% of lactulose and 24 wt.% of different aldose carbohydrates, was carried out at the optimal extraction conditions attained in the study of binary mixtures. The selective extraction of the ketosugar lactulose was also observed in this case, obtaining an extract with 81 wt.% lactulose and around 67% yield.

This work presents the main results attained by our research group merging chemical reaction, supercritical fluid extraction, thermodynamic phase equilibrium modeling and chemical analysis to study alternative supercritical extraction processes related with oil-type materials. Different fatty oil raw materials were fractionated in a countercurrent packed column using supercritical carbon dioxide and following different process targets, such as the deacidification of lampante olive oil and the recovery of minor lipid compounds (squalene, tocopherols and phytosterols) from industrial byproducts and wastes. If necessary, in order to facilitate the concentration of the preferred minor lipids in the raffinate product, the raw material employed was previously esterified. The GC-EoS model was used as the thermodynamic tool to represent phase equilibria behavior of the multicomponent oil-type material + CO2 mixture, and was employed to guide experiments so as to simulate and optimize the supercritical extraction processes. The coupling of thermodynamic modeling with experimental work has offered an efficient low-time consuming tool to analyze the viability of supercritical extraction processes.

The Group Contribution Equation of State (GC-EoS) was developed by Skjold–Jorgensen in 1984 for predicting phase equilibria of non-polar and polar mixtures. Since the model development, the GC-EoS group parameter table has been revised and extended, and the predictive capability of the model has been widely spread. Furthermore, the model has been successfully applied in the phase equilibria modeling of separation processes, particularly those related with supercritical fluids, and has also been used as a predictive tool for process simulation and optimization. This work is a comprehensive review of the present status of the GC-EoS parameter table, including revisions and extensions carried out by different authors since the model development until present. For a better understanding, available parameters are reported and organized in adequate tables. Additionally, the parameters for the carboxylic acid (COOH) group, which allow the modeling of an important family of compounds, i.e. carboxylic acids, are included in the present work. The application of the model to represent phase equilibria in mixtures of carbon dioxide and the main constituents of edible oils and derived products, demonstrate the capability of the model to be used in supercritical fluid oil-process simulation and optimization.

Ethanolysis of a raffinate product-obtained after distillation of olive oil-catalyzed by three commercial lipases (from Candida antarctica, Rhizomucor miehei and Thermomyces lanuginosa) was studied. Uni-response model derived from a generalized Michaelis–Menten mechanism was utilized to describe the rates of formation of ethyl esters from the fatty acids present in the precursor oil. The rate constants for the ethanolysis of triacylglycerols and steryl esters under the reaction conditions were compared. Moreover, inactivation of three lipases was evaluated. Because the half-life of the enzyme is comparable to or even shorter than the half-life of the reaction, the intrinsic reaction rate and enzyme deactivation must both be considered in modeling the kinetics.

The purification of squalene from residues of the olive oil deodorization process using countercurrent supercritical carbon dioxide extraction was studied. The raw material employed is a by-product obtained after distillation and ethylation of olive oil deodorizer distillates. This by-product contains mainly squalene and fatty acid esters. The Group Contribution Equation of State was employed to simulate the separation process and to design the experimental extractions, which were carried out in an isothermal countercurrent column, without reflux, at 343 K, pressures ranging from 150 to 230 bar and a solvent-to-feed ratio around 13. Satisfactory agreement was found between experimental and calculated yields and phase compositions, obtaining a raffinate product with a squalene concentration up to 90 wt.%. Finally, the thermodynamic model was employed to find out optimal process conditions to enhance squalene recovery, including partial reflux of the extract product and recirculation of the supercritical solvent in a continuous countercurrent extraction column.

Specially designed chromatographic columns were evaluated for antioxidant compounds separation by supercritical fluid chromatography (SFC) with pure CO2. Columns studied involved the use of commercial octadecylsilica particles (ODS) and silica particles coated with a stationary phase commonly used in gas chromatography, such as CW20M (polyethylene glycol) of high polarity. In order to select the appropriate chromatographic conditions to elute antioxidant compounds of phenolic structure, carnosic acid was selected as a model molecule and a theoretical study of the solubility of carnosic acid was performed. Carnosic acid was eluted using CO2 as mobile phase (without modifiers) with a pressure programming up to 37 MPa (and at different temperatures) but only when coated particles were used. No elution was possible when ODS particles were tested, probably due to the strong interactions of the acid group of the molecule with the active sites remaining in the column. A separation of a complex mixture of a rosemary antioxidant extract (obtained by supercritical fluid extraction) using the columns designed in the present work is shown.

The present study is devoted to the experimental measurement and thermodynamic modeling of solid carnosic acid solubility in supercritical CO 2 + ethanol as a co-solvent. Measurements were carried out at temperatures in the range of 313.15 and 333.15 K, pressures ranging from 280 to 400 bar, and at different content of the modifier ethanol (from 0.7 to 10%). The Group Contribution Associating Equation of State (GCA-EoS) [H.P. Gros, S.B. Bottini, E.A. Brignole, High pressure phase equilibrium modeling of mixtures containing associating compounds and gases, Fluid Phase Equilibria 139 (1997) 75–87] was applied in this work to represent the experimental solubility data obtained. Due to the lack of information in the literature about pure carnosic acid parameters, its solid volume, critical properties, and sublimation pressures were estimated in this work. The key step in the thermodynamic modeling proved to be the introduction of a solute hard-sphere parameter in the Carnahan–Starling repulsive term of the model, which depends on both temperature and pressure.

In this work, the Group Contribution Associating Equation of State (GCA-EoS) parameter table is extended in order to represent phase equilibrium behavior of aromatic compound mixtures, which contain the aromatic ether (ACOCH3), the phenol (ACOH) and the aromatic acid (ACCOOH) groups. Pure-group parameters and interaction parameters between these groups and the paraffin (CH3, CH2) and aromatic (ACH, AC, ACCH3) groups were estimated using experimental phase equilibrium data on binary mixtures. Also, their interaction parameters with water and carbon dioxide are reported. The extended parameter table is applied to predict high-pressure phase equilibria in binary and ternary mixtures containing high value complex aromatic compounds and carbon dioxide.

Grape seeds extracts have shown a broad range of pharmacological activities including, among others, antiulcer and antioxidant properties, which are mainly attributed to the phenolic compounds present. To date, the most abundant phenolic compounds isolated from grape seeds are catechins and their derivatives, e.g. quercetin. The present study is devoted to the experimental measurement and thermodynamic modelling of the solubility of quercetin in supercritical CO 2 + ethanol as a co-solvent. The solubility of quercetin was measured at 313.15 K, pressures ranging from 80 to 120 bar, and at different content of the modifier ethanol—from 5 to 30%. Two types of thermodynamic models were applied to model the solubility of quercetin—the group contribution equation of state (GC-EoS), developed by Skjold–Jogensen, and the Soave–Redlich–Kwong (SRK) EoS.

This contribution reports new experimental data on the fluid phase behavior of binary mixtures of carbon dioxide and three saturated, low-molecular weight triglycerides: tributyrin, tricaproin and tricaprylin. The objective of this work is to analyze the effect of the triglyceride molecular weight on the phase behavior of mixtures with carbon dioxide. The experimental work covers a temperature range between 276 and 368 K and pressures up to 15 MPa. All mixtures show liquid-liquid immiscibility near the critical point of pure carbon dioxide. From the analysis of the experimental data, it became apparent that the CO2-systems with tricaproin and tricaprylin have both type-IV fluid phase behavior in the classification of Van Konynenburg and Scott. The fluid phase behavior of these systems was modeled with the group contribution equation of state GC-EoS. The equation was able to describe vapor-liquid, liquid-liquid and vapor-liquid-liquid equilibria, with a single set of group interaction parameters. Fil: Florusse, L.J.. Delft University of Technology; Países Bajos Fil: Fornari Reali, Tiziana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina Fil: Bottini, Susana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina Fil: Peters, C.J.. Delft University of Technology; Países Bajos

The Group Contribution Equation of State (GC-EOS) is applied to model high-pressure phase equilibria in mixtures of fatty oils and acid alkyl esters with supercritical fluids. The fatty oil is represented by a pseudo-triacylglyceride with the same molecular weight and degree of unsaturation of the natural oil. The critical hard sphere diameter of the oil, i.e. the size-related parameter, is determined from the correlation of infinite dilution activity coefficients of n -alkanes in high molecular weight triacylglicerides and hydrocarbons. Good predictions of vapor–liquid, liquid–liquid and vapor–liquid–liquid equilibria in mixtures of supercritical solvents (propane, ethane and CO 2 ) with pure triacylglycerides, natural vegetable oils and fatty acid alkyl esters are obtained. These results show the capability of the GC-EOS model to describe the phase equilibria of size-asymmetric mixtures and its potential for modeling supercritical processes involving oils and derivatives.

This contribution reports new experimental data on the phase behavior of the binary system dimethylether (DME)+tripalmitin (PPP). The experimental work covers a temperature region between 275 and 450 K and pressures up to 12 MPa were applied. Near the critical point of pure DME a three-phase region liquid–liquid–vapor (l1l2g) was established. Although only an upper critical endpoint of this three-phase equilibrium could be determined experimentally, it is most likely that the system DME+PPP belongs to type-V fluid phase behavior in the classification of Van Konynenburg and Scott. Besides the fluid phase behavior of the system, also phase equilibria in the presence of solid PPP were measured. From earlier work it became apparent that a Group Contribution Equation of State is capable to model the vapor–liquid and liquid–liquid equilibria in related systems. Therefore, this equation also was chosen to model the fluid phase behavior of the system DME+PPP.

The group contribution equation of state GC-EOS model is revised and extended. Pure group and binary interaction parameters are reported for the following new groups: ether CH2O, ester CH2COO/CH3COO, chloro-aromatic ACCl and triglyceride (TG) (CH2COO)2CHCOO.Interaction parameters between these groups and paraffin, olefin and CO2 groups were estimated using experimental vapor-liquid equilibrium data on binary mixtures. The original aromatic-paraffinic, CO2-paraffinic and CO2-aromatic interaction parameters, have been revised in order to improve phase equilibrium predictions in aromatic and high molecular weight organic compounds. Fil: Espinosa, Susana Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina Fil: Foco, Gloria Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina Fil: Bermúdez, A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina Fil: Fornari, T.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina

The Group Contribution Equation of State (GC-EOS) is applied to calculate vapor–liquid and liquid–liquid equilibria of supercritical alkane–vegetable oil mixtures. A new functional group is defined, in order to represent the triglyceride nucleus of vegetable oil molecules. Pure group and binary interaction parameters for this group are given. The size of the high molecular weight triglyceride component is characterized by fitting its critical hard sphere diameter to infinite dilution activity coefficient data of hydrocarbons in the triglyceride.

Phase equilibria of ternary ethane propane-sunflower oil mixtures were measured at 313, 333 and 353 K, and at pressures of up to 120 bar. The region of partial liquid miscibility, at high hydrocarbon concentration, was particularly explored. The Soave-Redlich-Kwong equation of state was used to fit experimental vapor-liquid and liquid-liquid equilibria of alkane-vegetable oil mixtures. The application of a quadratic mixing rule for the co-volume b with a binary interaction coefficient kbij greatly improves the performance of the model.

A reactive system, with a number of species larger than the number of elements involved, has meaningful invariant algebraic properties in the space of the Gibbs function of reaction and temperature These properties, developed for a reactive system with two degrees of freedom, show that an, in principle, an infinite number of reactions can be reduced to smaller clusters whose thermodynamic feasibility can be evaluated through simple measures. The invariant algebraic properties of reactive systems in the [Δ G , T ] space, together with the definition of a bounded feasibility region in the same space, allow the formulation of a search algorithm, which is used for the synthesis of feasible chemical production schemes. These ideas are demonstrated in an application to C 1 chemistry, indicating that the approach developed can generate reaction paths some of which coincide with existing commercial processes.