Tiziana Fornari - Academia.edu (original) (raw)

Papers by Tiziana Fornari

Procedimiento para la obtención de extracto de lúpulo y extracto obtenido. La presente invención ... more Procedimiento para la obtención de extracto de lúpulo y extracto obtenido. La presente invención se refiere a un procedimiento para la obtención de extracto de lúpulo enriquecido en isoxantohumol, y al extracto obtenido mediante dicho procedimiento.

International Journal of Food Science & Technology, 2014

The Journal of Supercritical Fluids, 2002

... Author Keywords: Phase equilibria; Thermodynamic modeling; Group contribution; Triglycerides;... more ... Author Keywords: Phase equilibria; Thermodynamic modeling; Group contribution; Triglycerides; Vegetable oils. ... the calculation of both, the attractive energy parameter (a) and the co-volume (b), in ... However, it was not possible to correlate the VLE and LLE data using the same ...

The Journal of Supercritical Fluids, 2011

The Journal of Supercritical Fluids, 2011

Rosmarinus officinalis (rosemary) extracts were obtained in a supercritical pilot-scale plant. Ba... more Rosmarinus officinalis (rosemary) extracts were obtained in a supercritical pilot-scale plant. Based on experimental information available in the literature for analytical or low-scale processes, extraction temperature and pressure were selected to be 313 K and 30 MPa. At these extraction conditions, the kinetic behavior of the pilot-scale overall extraction curve were determined with respect to yield, antioxidant activity and carnosic acid content. The overall extraction curve was represented using Sovova's model; the average deviation between measured and calculated yields was lower than 2%. Mass transfer coefficients in the fluid and solid phases were determined and were compared with previous data reported in the literature for low-scale rosemary supercritical extraction. A two-stage depressurization procedure was accomplished and the effect of both on-line fractionation and extraction time on the antioxidant activity of the samples collected was studied. The antioxidant activity of the different fractions could be straight correlated with the carnosic acid content with a regression coefficient of 0.92.

The Journal of Supercritical Fluids, 2010

The supercritical removal of ethanol from alcoholic beverages (brandy, wine, and cider) was studi... more The supercritical removal of ethanol from alcoholic beverages (brandy, wine, and cider) was studied using the GC-EoS model to represent the phase equilibria behavior of the CO 2 + beverage mixture. Each alcoholic drink was represented as the ethanol + water mixture with the corresponding ethanol concentration (35 wt% for brandy, 9-12 wt% for different wines and 6 wt% for cider). The thermodynamic modeling was based on an accurate representation of the CO 2 + ethanol and CO 2 + water binary mixtures, and the CO 2 + ethanol + water ternary mixture. The GC-EoS model was employed to simulate the countercurrent supercritical CO 2 dealcoholization of the referred beverages; the results obtained compared good with experimental data from the literature. Thus, the model was used to estimate process conditions to achieve an ethanol content reduction from ca. 10 wt% to values lower than 1 wt%. The model results were tested by carrying out several extraction assays using wine, in a 3 m height packed column at 308 K, pressures in the range of 9-18 MPa and solvent to wine ratio between 9 and 30 kg/kg.

The Journal of Supercritical Fluids, 2009

The removal of ethanol from alcoholic beverages using supercritical carbon dioxide (CO 2) as solv... more The removal of ethanol from alcoholic beverages using supercritical carbon dioxide (CO 2) as solvent was studied considering the CO 2 + ethanol + water mixture as model system. The extensive phase equilibria data reported in the literature for this ternary system, together with new experimental data of different CO 2 + alcoholic beverage mixtures, were employed to analyze the effect of temperature and pressure on the phase behavior of the supercritical dealcoholization process. It was demonstrated that phase envelopes and tie-lines of the ternary CO 2 + ethanol + water phase diagram depend on CO 2 density. Thus, different combinations of extraction temperature and pressure can produce the same removal of ethanol from the alcoholic beverage. The GC-EoS thermodynamic model was used to represent phase equilibria behavior and to simulate a countercurrent multistage dealcoholization process. Despite extraction temperature and pressure, at constant CO 2 density almost the same elimination of ethanol was attained and the concentration of ethanol in the dealcoholized product was mainly determined by the ratio between the solvent to beverage flows.

The Journal of Supercritical Fluids, 2010

The Journal of Supercritical Fluids, 2009

Prebiotic carbohydrates are defined as non-digestible carbohydrates that beneficially affect the ... more 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.

The Journal of Supercritical Fluids, 2005

The present study is devoted to the experimental measurement and thermodynamic modeling of solid ... more 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.

Journal of Food Engineering, 2009

Supercritical carbon dioxide was used as an extractive solvent to remove free fatty acids from co... more Supercritical carbon dioxide was used as an extractive solvent to remove free fatty acids from coldpressed 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.

Journal of Chromatography A, 2012

Production of prebiotic carbohydrates at competitive prices is a challenge nowadays since the wel... more Production of prebiotic carbohydrates at competitive prices is a challenge nowadays since the wellestablished 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.

Journal of Chemical & Engineering Data, 2011

Experimental and modeling studies of the liquid-liquid equilibria at ambient pressure of three mo... more Experimental and modeling studies of the liquid-liquid equilibria at ambient pressure of three model systemssqualene þ ethyl lactate, olive oil þ ethyl lactate, and squalene þ olive oil þ ethyl lactate-were performed with the view to explore the potential application of an agrochemical solvent, namely, ethyl lactate, to recover squalene from pretreated olive oil deodorizer distillate. The favorable separation factors obtained reveal the strength and potential of ethyl lactate as a green solvent for the recovery of squalene from squalene þ triglyceride mixtures. ' MATERIALS AND METHODS Chemicals. Squalene (98 % mass purity) and ethyl lactate (98 % mass purity) were obtained from Sigma-Aldrich (St. Louis, MO, USA). Extra virgin olive oil was purchased from a food store. Reagents for chemical analysis, trimethyl-2,2,4 pentane, methylt-butyl-ether, propan-2-ol, and chloroform, were of HPLC grade (Lab Scan, Dublin). Experimental Procedure. Transition Temperature Determination. Transition temperatures define the liquid-liquid region of a system and are usually determined by the cloud-point method, observing visually the onset of the phase transition.

Journal of Chemical & Engineering Data, 2010

... from Olive Oil Distillates JAOCS 1993, 70, 763– 766 ... Chem. 1993, 97, 597– 603. 16. Cismond... more ... from Olive Oil Distillates JAOCS 1993, 70, 763– 766 ... Chem. 1993, 97, 597– 603. 16. Cismondi, M.; Mollerup, J.; Brignole, EA; Zabaloy, MS Modelling the high-pressure phase equilibria of carbon dioxide - triglyceride systems: A parameterization strategy Fluid Phase Equilib. ...

Journal of Chemical & Engineering Data, 2006

Measurements of D-pinitol solubility in supercritical CO 2 in the temperature range (313 to 333) ... more Measurements of D-pinitol solubility in supercritical CO 2 in the temperature range (313 to 333) K and pressures ranging from 10 to 40 MPa are reported for the first time in this work. Two different thermodynamic models are applied to correlate the experimental D-pinitol solubilities: a cubic-type equation of state (the Soave-Redlich-Kong, SRK) and a model based on the group contribution approach (the Group Contribution Equation of State, GC-EoS). Both models demonstrate high capability to describe the solid-gas-phase equilibria of this system. In addition, values for the thermophysical properties, sublimation pressure, and solid molar volume of D-pinitol are also given.

Journal of Chemical & Engineering Data, 2007

ABSTRACT Solubility data of solid 3,4,5-trihydroxybenzoic acid (gallic acid) in supercritical CO2... more ABSTRACT Solubility data of solid 3,4,5-trihydroxybenzoic acid (gallic acid) in supercritical CO2 + ethanol as a cosolvent are reported in this work. Measurements were carried out in the temperature range (313.15 to 333.15) K, pressures ranging from (10 to 40) MPa, and different ethanol modifier content ranging from (0.7 to 6) %. The experimental data were correlated using the Soave−Redlich−Kwong equation of state and the group contribution associating equation of state. The thermodynamic modeling analysis includes also the solubility representation of an important class of natural antioxidants (e.g., gallic acid esters) in supercritical CO2.

Journal of Chemical & Engineering Data, 2008

Carbon dioxide can act as an expanding medium to carry out enzymatic reactions. Particularly, by ... more Carbon dioxide can act as an expanding medium to carry out enzymatic reactions. Particularly, by dissolving CO 2 in mixtures comprising lipid-type substances and simultaneously increasing the pressure, the miscibility among reactants is enhanced, viscosity of the reaction mixture decreases, and diffusion of reactants and products is improved. Knowledge about the phase equilibrium behavior of the reactive mixture + CO 2 allows an adequate selection of conditions to achieve the homogeneous phase during reaction. In this work, phase equilibria data of the pseudoternary system sunflower oil + ethanol + CO 2 at two different conditions (313 K and 13 MPa; 333 K and 20 MPa) were investigated to provide an understanding of the phase behavior of vegetable oil ethanolysis reactions in CO 2-expanded media. Measurements were carried out by the analytical static method, using a variable-volume view cell equipped with a cold end light and a magnetic stirrer. Experimental tie-lines were determined for both types of equilibria observed: liquid + liquid and liquid + supercritical phase equilibria. Additionally, the experimental compositions obtained were correlated using a group contribution thermodynamic model.

Journal of the American Oil Chemists’ Society, 1994

The prediction of the vapor-llquid equilibria of vegetable oil-hexane mixtures is studied. Activi... more The prediction of the vapor-llquid equilibria of vegetable oil-hexane mixtures is studied. Activity coefficients are calculated by the UNIFAC model. Different entropic contributions to activity coefficients from the literature are analyzed. These modifications improve the performance of the original UNIFAC model in vapor-liquid equilibrium calculations.

Journal of the American Oil Chemists' Society, 2013

Low-menthol or dementholized oils can be regarded as potential sources of biocidal compounds, par... more Low-menthol or dementholized oils can be regarded as potential sources of biocidal compounds, particularly monoterpenic ketones such as menthone, piperitone, piperitenone, pulegone and carvone. In this work, the recovery of piperitenone from peppermint oil by supercritical carbon dioxide fractionation is studied. Separation selectivity and gas loading measurements were performed in a semicontinuous highpressure apparatus in order to evaluate the effect of temperature and solvent density on these properties. Semicontinuous fractionation was also carried out at a fixed temperature (313 K) and pressure (85 bar), collecting and analyzing extract samples until a purified piperitenone raffinate was obtained. The phase behavior of the system was modeled and predicted with the group contribution equation of state (GC-EOS). Good agreement with the experimental results was obtained. Finally, a continuous countercurrent multistage fractionation process was simulated, based on the GC-EOS model. The effect of operation temperature and pressure, solvent-to-feed ratio and reflux ratio was studied for different purity and recovery requirements and oil feed compositions.

Food and Bioproducts Processing, 2013

This paper reports experimental data on the pressurized liquid extraction of caffeine from green ... more This paper reports experimental data on the pressurized liquid extraction of caffeine from green coffee beans and green tea leaves using ethyl lactate (ethyl 2-hydroxy-propanoate). This solvent is a new bio-renewable agrochemical solvent, naturally produced by fermentation from corn derived feedstock, which has been recently considered as a very suitable and environmental benign solvent for food industrial applications. Static extraction assays (one step during 10 min) were carried out in an Accelerated solvent extraction (ASE) system at three different extraction temperatures, namely 100, 150 and 200 • C. Extraction yield and caffeine recovery were determined and compared with those obtained when using other liquid solvents, such as ethyl acetate or ethanol. High recovery of caffeine (≈60%) was found in the extracts produced using ethyl lactate, which demonstrates the potential use of this green solvent for the extraction of caffeine from different vegetable sources.

Procedimiento para la obtención de extracto de lúpulo y extracto obtenido. La presente invención ... more Procedimiento para la obtención de extracto de lúpulo y extracto obtenido. La presente invención se refiere a un procedimiento para la obtención de extracto de lúpulo enriquecido en isoxantohumol, y al extracto obtenido mediante dicho procedimiento.

International Journal of Food Science & Technology, 2014

The Journal of Supercritical Fluids, 2002

... Author Keywords: Phase equilibria; Thermodynamic modeling; Group contribution; Triglycerides;... more ... Author Keywords: Phase equilibria; Thermodynamic modeling; Group contribution; Triglycerides; Vegetable oils. ... the calculation of both, the attractive energy parameter (a) and the co-volume (b), in ... However, it was not possible to correlate the VLE and LLE data using the same ...

The Journal of Supercritical Fluids, 2011

The Journal of Supercritical Fluids, 2011

Rosmarinus officinalis (rosemary) extracts were obtained in a supercritical pilot-scale plant. Ba... more Rosmarinus officinalis (rosemary) extracts were obtained in a supercritical pilot-scale plant. Based on experimental information available in the literature for analytical or low-scale processes, extraction temperature and pressure were selected to be 313 K and 30 MPa. At these extraction conditions, the kinetic behavior of the pilot-scale overall extraction curve were determined with respect to yield, antioxidant activity and carnosic acid content. The overall extraction curve was represented using Sovova's model; the average deviation between measured and calculated yields was lower than 2%. Mass transfer coefficients in the fluid and solid phases were determined and were compared with previous data reported in the literature for low-scale rosemary supercritical extraction. A two-stage depressurization procedure was accomplished and the effect of both on-line fractionation and extraction time on the antioxidant activity of the samples collected was studied. The antioxidant activity of the different fractions could be straight correlated with the carnosic acid content with a regression coefficient of 0.92.

The Journal of Supercritical Fluids, 2010

The supercritical removal of ethanol from alcoholic beverages (brandy, wine, and cider) was studi... more The supercritical removal of ethanol from alcoholic beverages (brandy, wine, and cider) was studied using the GC-EoS model to represent the phase equilibria behavior of the CO 2 + beverage mixture. Each alcoholic drink was represented as the ethanol + water mixture with the corresponding ethanol concentration (35 wt% for brandy, 9-12 wt% for different wines and 6 wt% for cider). The thermodynamic modeling was based on an accurate representation of the CO 2 + ethanol and CO 2 + water binary mixtures, and the CO 2 + ethanol + water ternary mixture. The GC-EoS model was employed to simulate the countercurrent supercritical CO 2 dealcoholization of the referred beverages; the results obtained compared good with experimental data from the literature. Thus, the model was used to estimate process conditions to achieve an ethanol content reduction from ca. 10 wt% to values lower than 1 wt%. The model results were tested by carrying out several extraction assays using wine, in a 3 m height packed column at 308 K, pressures in the range of 9-18 MPa and solvent to wine ratio between 9 and 30 kg/kg.

The Journal of Supercritical Fluids, 2009

The removal of ethanol from alcoholic beverages using supercritical carbon dioxide (CO 2) as solv... more The removal of ethanol from alcoholic beverages using supercritical carbon dioxide (CO 2) as solvent was studied considering the CO 2 + ethanol + water mixture as model system. The extensive phase equilibria data reported in the literature for this ternary system, together with new experimental data of different CO 2 + alcoholic beverage mixtures, were employed to analyze the effect of temperature and pressure on the phase behavior of the supercritical dealcoholization process. It was demonstrated that phase envelopes and tie-lines of the ternary CO 2 + ethanol + water phase diagram depend on CO 2 density. Thus, different combinations of extraction temperature and pressure can produce the same removal of ethanol from the alcoholic beverage. The GC-EoS thermodynamic model was used to represent phase equilibria behavior and to simulate a countercurrent multistage dealcoholization process. Despite extraction temperature and pressure, at constant CO 2 density almost the same elimination of ethanol was attained and the concentration of ethanol in the dealcoholized product was mainly determined by the ratio between the solvent to beverage flows.

The Journal of Supercritical Fluids, 2010

The Journal of Supercritical Fluids, 2009

Prebiotic carbohydrates are defined as non-digestible carbohydrates that beneficially affect the ... more 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.

The Journal of Supercritical Fluids, 2005

The present study is devoted to the experimental measurement and thermodynamic modeling of solid ... more 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.

Journal of Food Engineering, 2009

Supercritical carbon dioxide was used as an extractive solvent to remove free fatty acids from co... more Supercritical carbon dioxide was used as an extractive solvent to remove free fatty acids from coldpressed 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.

Journal of Chromatography A, 2012

Production of prebiotic carbohydrates at competitive prices is a challenge nowadays since the wel... more Production of prebiotic carbohydrates at competitive prices is a challenge nowadays since the wellestablished 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.

Journal of Chemical & Engineering Data, 2011

Experimental and modeling studies of the liquid-liquid equilibria at ambient pressure of three mo... more Experimental and modeling studies of the liquid-liquid equilibria at ambient pressure of three model systemssqualene þ ethyl lactate, olive oil þ ethyl lactate, and squalene þ olive oil þ ethyl lactate-were performed with the view to explore the potential application of an agrochemical solvent, namely, ethyl lactate, to recover squalene from pretreated olive oil deodorizer distillate. The favorable separation factors obtained reveal the strength and potential of ethyl lactate as a green solvent for the recovery of squalene from squalene þ triglyceride mixtures. ' MATERIALS AND METHODS Chemicals. Squalene (98 % mass purity) and ethyl lactate (98 % mass purity) were obtained from Sigma-Aldrich (St. Louis, MO, USA). Extra virgin olive oil was purchased from a food store. Reagents for chemical analysis, trimethyl-2,2,4 pentane, methylt-butyl-ether, propan-2-ol, and chloroform, were of HPLC grade (Lab Scan, Dublin). Experimental Procedure. Transition Temperature Determination. Transition temperatures define the liquid-liquid region of a system and are usually determined by the cloud-point method, observing visually the onset of the phase transition.

Journal of Chemical & Engineering Data, 2010

... from Olive Oil Distillates JAOCS 1993, 70, 763– 766 ... Chem. 1993, 97, 597– 603. 16. Cismond... more ... from Olive Oil Distillates JAOCS 1993, 70, 763– 766 ... Chem. 1993, 97, 597– 603. 16. Cismondi, M.; Mollerup, J.; Brignole, EA; Zabaloy, MS Modelling the high-pressure phase equilibria of carbon dioxide - triglyceride systems: A parameterization strategy Fluid Phase Equilib. ...

Journal of Chemical & Engineering Data, 2006

Measurements of D-pinitol solubility in supercritical CO 2 in the temperature range (313 to 333) ... more Measurements of D-pinitol solubility in supercritical CO 2 in the temperature range (313 to 333) K and pressures ranging from 10 to 40 MPa are reported for the first time in this work. Two different thermodynamic models are applied to correlate the experimental D-pinitol solubilities: a cubic-type equation of state (the Soave-Redlich-Kong, SRK) and a model based on the group contribution approach (the Group Contribution Equation of State, GC-EoS). Both models demonstrate high capability to describe the solid-gas-phase equilibria of this system. In addition, values for the thermophysical properties, sublimation pressure, and solid molar volume of D-pinitol are also given.

Journal of Chemical & Engineering Data, 2007

ABSTRACT Solubility data of solid 3,4,5-trihydroxybenzoic acid (gallic acid) in supercritical CO2... more ABSTRACT Solubility data of solid 3,4,5-trihydroxybenzoic acid (gallic acid) in supercritical CO2 + ethanol as a cosolvent are reported in this work. Measurements were carried out in the temperature range (313.15 to 333.15) K, pressures ranging from (10 to 40) MPa, and different ethanol modifier content ranging from (0.7 to 6) %. The experimental data were correlated using the Soave−Redlich−Kwong equation of state and the group contribution associating equation of state. The thermodynamic modeling analysis includes also the solubility representation of an important class of natural antioxidants (e.g., gallic acid esters) in supercritical CO2.

Journal of Chemical & Engineering Data, 2008

Carbon dioxide can act as an expanding medium to carry out enzymatic reactions. Particularly, by ... more Carbon dioxide can act as an expanding medium to carry out enzymatic reactions. Particularly, by dissolving CO 2 in mixtures comprising lipid-type substances and simultaneously increasing the pressure, the miscibility among reactants is enhanced, viscosity of the reaction mixture decreases, and diffusion of reactants and products is improved. Knowledge about the phase equilibrium behavior of the reactive mixture + CO 2 allows an adequate selection of conditions to achieve the homogeneous phase during reaction. In this work, phase equilibria data of the pseudoternary system sunflower oil + ethanol + CO 2 at two different conditions (313 K and 13 MPa; 333 K and 20 MPa) were investigated to provide an understanding of the phase behavior of vegetable oil ethanolysis reactions in CO 2-expanded media. Measurements were carried out by the analytical static method, using a variable-volume view cell equipped with a cold end light and a magnetic stirrer. Experimental tie-lines were determined for both types of equilibria observed: liquid + liquid and liquid + supercritical phase equilibria. Additionally, the experimental compositions obtained were correlated using a group contribution thermodynamic model.

Journal of the American Oil Chemists’ Society, 1994

The prediction of the vapor-llquid equilibria of vegetable oil-hexane mixtures is studied. Activi... more The prediction of the vapor-llquid equilibria of vegetable oil-hexane mixtures is studied. Activity coefficients are calculated by the UNIFAC model. Different entropic contributions to activity coefficients from the literature are analyzed. These modifications improve the performance of the original UNIFAC model in vapor-liquid equilibrium calculations.

Journal of the American Oil Chemists' Society, 2013

Low-menthol or dementholized oils can be regarded as potential sources of biocidal compounds, par... more Low-menthol or dementholized oils can be regarded as potential sources of biocidal compounds, particularly monoterpenic ketones such as menthone, piperitone, piperitenone, pulegone and carvone. In this work, the recovery of piperitenone from peppermint oil by supercritical carbon dioxide fractionation is studied. Separation selectivity and gas loading measurements were performed in a semicontinuous highpressure apparatus in order to evaluate the effect of temperature and solvent density on these properties. Semicontinuous fractionation was also carried out at a fixed temperature (313 K) and pressure (85 bar), collecting and analyzing extract samples until a purified piperitenone raffinate was obtained. The phase behavior of the system was modeled and predicted with the group contribution equation of state (GC-EOS). Good agreement with the experimental results was obtained. Finally, a continuous countercurrent multistage fractionation process was simulated, based on the GC-EOS model. The effect of operation temperature and pressure, solvent-to-feed ratio and reflux ratio was studied for different purity and recovery requirements and oil feed compositions.

Food and Bioproducts Processing, 2013

This paper reports experimental data on the pressurized liquid extraction of caffeine from green ... more This paper reports experimental data on the pressurized liquid extraction of caffeine from green coffee beans and green tea leaves using ethyl lactate (ethyl 2-hydroxy-propanoate). This solvent is a new bio-renewable agrochemical solvent, naturally produced by fermentation from corn derived feedstock, which has been recently considered as a very suitable and environmental benign solvent for food industrial applications. Static extraction assays (one step during 10 min) were carried out in an Accelerated solvent extraction (ASE) system at three different extraction temperatures, namely 100, 150 and 200 • C. Extraction yield and caffeine recovery were determined and compared with those obtained when using other liquid solvents, such as ethyl acetate or ethanol. High recovery of caffeine (≈60%) was found in the extracts produced using ethyl lactate, which demonstrates the potential use of this green solvent for the extraction of caffeine from different vegetable sources.