Albertina Ribeiro - Academia.edu (original) (raw)
Papers by Albertina Ribeiro
The Journal of Supercritical Fluids, 1999
... The experimental results of supercritical CO 2 extraction on summer savory (Satureja hortensi... more ... The experimental results of supercritical CO 2 extraction on summer savory (Satureja hortensis L.) oil at pressures ranging from 12 to 18 MPa and at a temperature of 313 K are presented. ... Fig. 2. Percentage of solute collected as a function of pressure in the range 1018 MPa. ...
The Journal of Supercritical Fluids, 2009
Fig leaf gourd (Cucurbita ficifolia, Bouché) seeds oil was extracted in a Soxhlet apparatus (oil ... more Fig leaf gourd (Cucurbita ficifolia, Bouché) seeds oil was extracted in a Soxhlet apparatus (oil content of 43.5%) and by supercritical fluid extraction (SFE) in the temperature and pressure ranges of 308-318 K and 18-20 MPa, respectively. Both oil batches showed similar fatty acids compositions. Main fatty acids were 6-linoleic acid (about 60%), palmitic acid (about 15%) and oleic acid (about 14%). The induction time was used to determine the oxidative stability, 4.2 and 8.3 h being obtained for SFE extracted oil and n-hexane extracted oil, respectively. Regarding the kinetics of supercritical fluid extraction, the Sovová's model was selected and successfully applied to the description of the oil extraction curves. The fitted parameters, the overall mass transfer coefficient for the fluid phase, K f , and the overall mass transfer coefficient for the solid phase, K s , vary in the ranges 2.34-4.57 × 10 −2 s −1 and 1.73-4.34 × 10 −4 s −1 , respectively. The free oil content for milled seeds, f k , was calculated as 61%. These parameters are consistent with those published for several other oils.
The Journal of Supercritical Fluids, 2001
... [3] I Nykanen and L Nykanen, Flavour composition of lemon balm (Melissa officinalis L.) culti... more ... [3] I Nykanen and L Nykanen, Flavour composition of lemon balm (Melissa officinalis L.) cultivated in Finland, Lebensm.-Wiss. Technol. 19 (1986), p. 482. ... [8] T López-Arnoldos, M López-Serrano, A Ros Barceló, AA Calderón and JM Zapata, Spectrophotometric determination of ...
Fluid Phase Equilibria, 1993
ABSTRACT The extraction of peppermint with supercritical CO2 at pressures from 9 to 18 MPa, and t... more ABSTRACT The extraction of peppermint with supercritical CO2 at pressures from 9 to 18 MPa, and temperatures of 308 to 323 K have been studied. Recovery conditions were varied from 6 to 8 MPa and the extraction time was varied from 1 to 6 hours. The study of the antioxidant activity of peppermint residual extracts in sunflower oil was performed using a Rancimat method. The best protection factor versus concentration of extract curve was obtained for the extraction condition of 18 MPa, 323 K and 1 hour. The residues of the supercritical carbon dioxide extraction show a high antioxidant activity but it was mainly dependent on the pressure used. It is concluded that the methodology employed was convenient for obtaining extracts with antioxidant activity, having applications in the food and pharmaceutical industries.
Process Technology Proceedings, 1996
The extraction of essential oil from oregano-Origanum virens L.- using liquid carbon dioxide (7 M... more The extraction of essential oil from oregano-Origanum virens L.- using liquid carbon dioxide (7 MPa and 298 K) and supercritical carbon dioxide (10 and 15 MPa and 313 K) was investigated. Experimental results were obtained in a laboratory scale plant equipped with a 100 mL tubular extractor.During the extraction an unsteady process prevails. The present paper presents an unsteady state
The Journal of Supercritical Fluids, 2007
Acorn fruit oil of Quercus rotundifolia L. (holm-oak) was extracted with compressed carbon dioxid... more Acorn fruit oil of Quercus rotundifolia L. (holm-oak) was extracted with compressed carbon dioxide in the temperature range of 35-60 • C and in the pressure range of 12-21 MPa. The influences of particle size, CO 2 density, solvent flow rate, and extractor geometry were studied. Two different tubular extractors were used: extractor 1 of 0.2 L of capacity, internal diameter D = 45.7 mm, height/diameter ratio H/D = 1.5, and extractor 2 of 0.09 L of capacity, internal diameter D = 21.3 mm, and H /D = 12.
¹Centro de Engenharia Biológica e Química, DEQ, IST, Av. Rovisco Pais, 1049-001, Lisboa, Portugal... more ¹Centro de Engenharia Biológica e Química, DEQ, IST, Av. Rovisco Pais, 1049-001, Lisboa, Portugal ... Produção de extractos para a indústria alimentar: ... *Pessoa a quem deverá ser dirigida a correspondência. Tel: +21 8417582; Fax: +21 8419176; Email: ...
Journal of Chemical & Engineering Data
A vegetable oil typically consists of a range of triglycerides, approximately 10% diglycerides, a... more A vegetable oil typically consists of a range of triglycerides, approximately 10% diglycerides, and a small fraction of free fatty acids and other minor constituents. The use of supercritical carbon dioxide for solvent extraction is currently the subject of numerous investigations. The solubilities of triolein in supercritical carbon dioxide were measured over a temperature range of 308--328 K and at pressures between 8 and 20 MPa by the static method. The data were correlated by the model proposed by Chrastil and the modification proposed by Adachi and Lu and Del Valle and Aguilera.
The Journal of Supercritical Fluids, 2007
Acorn fruit oil of Quercus rotundifolia L. (holm-oak) was extracted with compressed carbon dioxid... more Acorn fruit oil of Quercus rotundifolia L. (holm-oak) was extracted with compressed carbon dioxide in the temperature range of 35-60 • C and in the pressure range of 12-21 MPa. The influences of particle size, CO 2 density, solvent flow rate, and extractor geometry were studied. Two different tubular extractors were used: extractor 1 of 0.2 L of capacity, internal diameter D = 45.7 mm, height/diameter ratio H/D = 1.5, and extractor 2 of 0.09 L of capacity, internal diameter D = 21.3 mm, and H /D = 12.
Journal of Chemical & Engineering Data, 1990
... Densities were determined with a 10-mL Brand pycnometer that was calibrated with redistilled ... more ... Densities were determined with a 10-mL Brand pycnometer that was calibrated with redistilled water at all the temperatures. ... Albertina Ribeiro and Gabrieia Bernardo-Gil * Departamento Engenharia Quimica, Znstituto Superior Tgcnico, ...
Journal of Chemical & Engineering Data, 1990
Refractive index and density are physical properties of ex-treme importance in the characterizati... more Refractive index and density are physical properties of ex-treme importance in the characterization and identification of materials. As a part of a complete work on the choice of solvents to extract organic acids, the densities and the refractive indices of some of these compounds were ...
Journal of Chemical & Engineering Data, 1995
... Solubilities of Triolein in Supercritical Cog M. Albertina Ribeiro and MG Bernardo-Gil* ... T... more ... Solubilities of Triolein in Supercritical Cog M. Albertina Ribeiro and MG Bernardo-Gil* ... The solubilities of triolein in supercritical carbon dioxide were measured over a temperature range of 308-328 K and at pressures between 8 and 20 MPa by the static method. ...
Fluid Phase Equilibria, 1989
... Chem. Fund., 15: 59-fi4. 14 Roberts, LR and JJ McKetta, 1962. ... Full Text via CrossRef | Vi... more ... Chem. Fund., 15: 59-fi4. 14 Roberts, LR and JJ McKetta, 1962. ... Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (1346). Bernardo-Gil and Soares, 1982M.G. Bernardo-Gil and LJS Soares, Vapor-Liquid equilibria: correlation of binary data, Rev Port. Quim. ...
Fluid Phase Equilibria, 1993
ABSTRACT Vapor-liquid equilibrium data for the binary systems β-pinene + limonene and β-pinene + ... more ABSTRACT Vapor-liquid equilibrium data for the binary systems β-pinene + limonene and β-pinene + p-cymene were determined at atmospheric pressure in an Othmer equilibrium still.Vapor pressures of pure components were measured and the data correlated with the Antoine equation.Parameters for the Van-Laar, Margules, Wilson, NRTL and UNIQUAC equations were calculated with the aid of a Nelder - Mead technique to minimize an objective function based on the total pressure.Predictions with the UNIFAC method were also obtained.
Chemical Product and Process Modeling, 2000
M. Mercedes Esquivel, Centre for Biological and Chemical ... M. Albertina Ribeiro, Centre for Bio... more M. Mercedes Esquivel, Centre for Biological and Chemical ... M. Albertina Ribeiro, Centre for Biological and Chemical ... M. Gabriela Bernardo-Gil, Centre for Biological and ... Recommended Citation: Esquivel, M. Mercedes; Ribeiro, M. Albertina; and Bernardo-Gil, M. Gabriela ...
The Journal of Supercritical Fluids, 2009
Fig leaf gourd (Cucurbita ficifolia, Bouché) seeds oil was extracted in a Soxhlet apparatus (oil ... more Fig leaf gourd (Cucurbita ficifolia, Bouché) seeds oil was extracted in a Soxhlet apparatus (oil content of 43.5%) and by supercritical fluid extraction (SFE) in the temperature and pressure ranges of 308-318 K and 18-20 MPa, respectively.
The Journal of Supercritical Fluids, 1999
... The experimental results of supercritical CO 2 extraction on summer savory (Satureja hortensi... more ... The experimental results of supercritical CO 2 extraction on summer savory (Satureja hortensis L.) oil at pressures ranging from 12 to 18 MPa and at a temperature of 313 K are presented. ... Fig. 2. Percentage of solute collected as a function of pressure in the range 1018 MPa. ...
The Journal of Supercritical Fluids, 2009
Fig leaf gourd (Cucurbita ficifolia, Bouché) seeds oil was extracted in a Soxhlet apparatus (oil ... more Fig leaf gourd (Cucurbita ficifolia, Bouché) seeds oil was extracted in a Soxhlet apparatus (oil content of 43.5%) and by supercritical fluid extraction (SFE) in the temperature and pressure ranges of 308-318 K and 18-20 MPa, respectively. Both oil batches showed similar fatty acids compositions. Main fatty acids were 6-linoleic acid (about 60%), palmitic acid (about 15%) and oleic acid (about 14%). The induction time was used to determine the oxidative stability, 4.2 and 8.3 h being obtained for SFE extracted oil and n-hexane extracted oil, respectively. Regarding the kinetics of supercritical fluid extraction, the Sovová's model was selected and successfully applied to the description of the oil extraction curves. The fitted parameters, the overall mass transfer coefficient for the fluid phase, K f , and the overall mass transfer coefficient for the solid phase, K s , vary in the ranges 2.34-4.57 × 10 −2 s −1 and 1.73-4.34 × 10 −4 s −1 , respectively. The free oil content for milled seeds, f k , was calculated as 61%. These parameters are consistent with those published for several other oils.
The Journal of Supercritical Fluids, 2001
... [3] I Nykanen and L Nykanen, Flavour composition of lemon balm (Melissa officinalis L.) culti... more ... [3] I Nykanen and L Nykanen, Flavour composition of lemon balm (Melissa officinalis L.) cultivated in Finland, Lebensm.-Wiss. Technol. 19 (1986), p. 482. ... [8] T López-Arnoldos, M López-Serrano, A Ros Barceló, AA Calderón and JM Zapata, Spectrophotometric determination of ...
Fluid Phase Equilibria, 1993
ABSTRACT The extraction of peppermint with supercritical CO2 at pressures from 9 to 18 MPa, and t... more ABSTRACT The extraction of peppermint with supercritical CO2 at pressures from 9 to 18 MPa, and temperatures of 308 to 323 K have been studied. Recovery conditions were varied from 6 to 8 MPa and the extraction time was varied from 1 to 6 hours. The study of the antioxidant activity of peppermint residual extracts in sunflower oil was performed using a Rancimat method. The best protection factor versus concentration of extract curve was obtained for the extraction condition of 18 MPa, 323 K and 1 hour. The residues of the supercritical carbon dioxide extraction show a high antioxidant activity but it was mainly dependent on the pressure used. It is concluded that the methodology employed was convenient for obtaining extracts with antioxidant activity, having applications in the food and pharmaceutical industries.
Process Technology Proceedings, 1996
The extraction of essential oil from oregano-Origanum virens L.- using liquid carbon dioxide (7 M... more The extraction of essential oil from oregano-Origanum virens L.- using liquid carbon dioxide (7 MPa and 298 K) and supercritical carbon dioxide (10 and 15 MPa and 313 K) was investigated. Experimental results were obtained in a laboratory scale plant equipped with a 100 mL tubular extractor.During the extraction an unsteady process prevails. The present paper presents an unsteady state
The Journal of Supercritical Fluids, 2007
Acorn fruit oil of Quercus rotundifolia L. (holm-oak) was extracted with compressed carbon dioxid... more Acorn fruit oil of Quercus rotundifolia L. (holm-oak) was extracted with compressed carbon dioxide in the temperature range of 35-60 • C and in the pressure range of 12-21 MPa. The influences of particle size, CO 2 density, solvent flow rate, and extractor geometry were studied. Two different tubular extractors were used: extractor 1 of 0.2 L of capacity, internal diameter D = 45.7 mm, height/diameter ratio H/D = 1.5, and extractor 2 of 0.09 L of capacity, internal diameter D = 21.3 mm, and H /D = 12.
¹Centro de Engenharia Biológica e Química, DEQ, IST, Av. Rovisco Pais, 1049-001, Lisboa, Portugal... more ¹Centro de Engenharia Biológica e Química, DEQ, IST, Av. Rovisco Pais, 1049-001, Lisboa, Portugal ... Produção de extractos para a indústria alimentar: ... *Pessoa a quem deverá ser dirigida a correspondência. Tel: +21 8417582; Fax: +21 8419176; Email: ...
Journal of Chemical & Engineering Data
A vegetable oil typically consists of a range of triglycerides, approximately 10% diglycerides, a... more A vegetable oil typically consists of a range of triglycerides, approximately 10% diglycerides, and a small fraction of free fatty acids and other minor constituents. The use of supercritical carbon dioxide for solvent extraction is currently the subject of numerous investigations. The solubilities of triolein in supercritical carbon dioxide were measured over a temperature range of 308--328 K and at pressures between 8 and 20 MPa by the static method. The data were correlated by the model proposed by Chrastil and the modification proposed by Adachi and Lu and Del Valle and Aguilera.
The Journal of Supercritical Fluids, 2007
Acorn fruit oil of Quercus rotundifolia L. (holm-oak) was extracted with compressed carbon dioxid... more Acorn fruit oil of Quercus rotundifolia L. (holm-oak) was extracted with compressed carbon dioxide in the temperature range of 35-60 • C and in the pressure range of 12-21 MPa. The influences of particle size, CO 2 density, solvent flow rate, and extractor geometry were studied. Two different tubular extractors were used: extractor 1 of 0.2 L of capacity, internal diameter D = 45.7 mm, height/diameter ratio H/D = 1.5, and extractor 2 of 0.09 L of capacity, internal diameter D = 21.3 mm, and H /D = 12.
Journal of Chemical & Engineering Data, 1990
... Densities were determined with a 10-mL Brand pycnometer that was calibrated with redistilled ... more ... Densities were determined with a 10-mL Brand pycnometer that was calibrated with redistilled water at all the temperatures. ... Albertina Ribeiro and Gabrieia Bernardo-Gil * Departamento Engenharia Quimica, Znstituto Superior Tgcnico, ...
Journal of Chemical & Engineering Data, 1990
Refractive index and density are physical properties of ex-treme importance in the characterizati... more Refractive index and density are physical properties of ex-treme importance in the characterization and identification of materials. As a part of a complete work on the choice of solvents to extract organic acids, the densities and the refractive indices of some of these compounds were ...
Journal of Chemical & Engineering Data, 1995
... Solubilities of Triolein in Supercritical Cog M. Albertina Ribeiro and MG Bernardo-Gil* ... T... more ... Solubilities of Triolein in Supercritical Cog M. Albertina Ribeiro and MG Bernardo-Gil* ... The solubilities of triolein in supercritical carbon dioxide were measured over a temperature range of 308-328 K and at pressures between 8 and 20 MPa by the static method. ...
Fluid Phase Equilibria, 1989
... Chem. Fund., 15: 59-fi4. 14 Roberts, LR and JJ McKetta, 1962. ... Full Text via CrossRef | Vi... more ... Chem. Fund., 15: 59-fi4. 14 Roberts, LR and JJ McKetta, 1962. ... Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (1346). Bernardo-Gil and Soares, 1982M.G. Bernardo-Gil and LJS Soares, Vapor-Liquid equilibria: correlation of binary data, Rev Port. Quim. ...
Fluid Phase Equilibria, 1993
ABSTRACT Vapor-liquid equilibrium data for the binary systems β-pinene + limonene and β-pinene + ... more ABSTRACT Vapor-liquid equilibrium data for the binary systems β-pinene + limonene and β-pinene + p-cymene were determined at atmospheric pressure in an Othmer equilibrium still.Vapor pressures of pure components were measured and the data correlated with the Antoine equation.Parameters for the Van-Laar, Margules, Wilson, NRTL and UNIQUAC equations were calculated with the aid of a Nelder - Mead technique to minimize an objective function based on the total pressure.Predictions with the UNIFAC method were also obtained.
Chemical Product and Process Modeling, 2000
M. Mercedes Esquivel, Centre for Biological and Chemical ... M. Albertina Ribeiro, Centre for Bio... more M. Mercedes Esquivel, Centre for Biological and Chemical ... M. Albertina Ribeiro, Centre for Biological and Chemical ... M. Gabriela Bernardo-Gil, Centre for Biological and ... Recommended Citation: Esquivel, M. Mercedes; Ribeiro, M. Albertina; and Bernardo-Gil, M. Gabriela ...
The Journal of Supercritical Fluids, 2009
Fig leaf gourd (Cucurbita ficifolia, Bouché) seeds oil was extracted in a Soxhlet apparatus (oil ... more Fig leaf gourd (Cucurbita ficifolia, Bouché) seeds oil was extracted in a Soxhlet apparatus (oil content of 43.5%) and by supercritical fluid extraction (SFE) in the temperature and pressure ranges of 308-318 K and 18-20 MPa, respectively.