Person: Calvo Garrido, María Lourdes
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First Name
María Lourdes
Last Name
Calvo Garrido
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Ingeniería Química y de Materiales
Area
Ingeniería Química
Identifiers
13 results
Search Results
Now showing 1 - 10 of 13
Item The Selective Supercritical Extraction of High-value Fatty Acids from Tetraselmis suecica using the Hansen Solubility Theory(Chemical engineering transactions, 2019) Calvo Garrido, Lourdes; Tirado Armesto, Diego Felipe; Rousset, Amandine; Calvo Garrido, María LourdesThe aim of this work was to test the utility of the Hansen theory to predict the best cosolvent for supercritical carbon dioxide (sc-CO2) to reach the selective extraction of fatty acids from Tetraselmis suecica. The order in the cosolvent power was established with five organic solvents used in food production: acetone, diethyl ether, ethanol, n-hexane and methanol. Predictions focused on the selective extraction of oleic, linoleic and αlinolenic acid. The cosolvent power depended on the fatty acid, but in general, the best cosolvent for the three target compounds was ethanol. Predictions were validated through equilibrium data and extraction yields from T. suecica. Operating at 305.15 K and 20 MPa, the extracted oil with the sc-CO2-ethanol (5 % mass fraction) mixture significantly improved the content of the target fatty acids compared with pure sc-CO2; e.g. the αlinolenic acid content was 16 % in the oil obtained with pure sc-CO2 while it was 25 % in the oil obtained with sc-CO2 + 5 % ethanol. However, the Hansen theory predicted that the miscibility enhancement of the fatty acids caused by increasing ethanol concentrations in the supercritical solvent mixture was not progressive. In fact, at high pressures and high ethanol concentrations, it was predicted up to less than half the miscibility enhancement.Item Inactivation of Clostridium Spores in Honey with Supercritical CO2 and in Combination with Essential Oils(Processes, 2022) Dacal Gutierrez, Alejandro; Tirado Armesto, Diego Felipe; Calvo Garrido, Lourdes; Calvo Garrido, María LourdesThe presence of tens of Clostridium botulinum spores per gram of honey can cause infantile botulism. Thermal treatment is insufficient to inactivate these resistant forms. This study explored the effectiveness of supercritical CO2 (scCO2 ) on its own and combined with lemon (LEO), clove (CLEO), and cinnamon (CEO) essential oils on the inactivation of Clostridium sporogenes (CECT 553) as a surrogate of Clostridium botulinum. In water, the degree of inactivation at 10 MPa after 60 min increased with the increasing temperature, reducing the population by 90% at 40 ◦C and by 99.7% at 80 ◦C. In contrast, when applied to honey, scCO2 did not inactivate Clostridium spores satisfactorily at temperatures below 70 ◦C, which was related to the protective effect of honey. Meanwhile, scCO2 modified with CEOItem One-step Sustainable Preparation of Superparamagnetic Iron Oxide Nanoparticles Supported on Mesoporous SiO2(Journal of Supercritical Fluids, 2020) Chamorro, Elena; Granados García Tenorio, María José; Calvo Garrido, María Lourdes; Torralvo Fernández, María José; Sáez Puche, Regino; Cabañas Poveda, AlbertinaSuperparamagnetic iron oxide nanoparticles (SPIONs) supported on high surface area mesoporous SiO2 are advanced materials of great interest in catalysis, adsorption and biomedicine. Here we present a new process to prepare SPION/SiO2 materials by the impregnation and insitu decomposition of Fe(NO3)3.9H2O on mesoporous SiO2 supports in a 25-50% mol ethanol + CO2 mixture at 523 K and 25.0 MPa. -Fe2O3 nanoparticles (NPs) of average size between 6-9 nm were distributed homogeneously on the supports. NPs deposited into the SBA-15 mesopores but mostly on the external surface of MCM-41. Materials prepared with the highest ethanol content were very homogeneous. Magnetic measurements confirmed the superparamagnetic nature of the materials at room temperature. The process proposed is sustainable and scalable, avoids tedious preparations and the additional high temperature treatment under a controlled atmosphere, as the metal decomposition is performed insitu in the CO2-expanded liquid mixture.Item A selective extraction of hydroxytyrosol rich olive oil from alperujo(Journal of Food Engineering, 2019) Calvo Garrido, Lourdes; Tirado Armesto, Diego Felipe; Fuente, Esther de la; Calvo Garrido, María LourdesAlperujo, the solid-liquid waste generated by the current two-phase method of olive oil extraction, was dried, milled and treated with supercritical carbon dioxide (sc-CO2) to obtain a hydroxytyrosol (HT)-rich oil. At first, extraction rates were analysed as a function of operating variables and the pre-condition of the raw material. Samples with particle size diameter<0.80mm and in equilibrium moisture (1%) with the atmosphere, improved oil extraction yield almost 40% compared with samples with the whole range of particle sizes. Extraction yield improved with solvent flow rate, but a minimum residence time was required. The optimum was 0.18 kg h−1 (7.5 kg CO2 h−1 kg biomass−1). Higher pressures and lower temperatures resulted in higher extraction yields; at 30 MPa and 323 K the extraction curve slope was close to the theoretical oil solubility and the yield was 13%, like that obtained with n-hexane by Soxhlet (14%). However, the HPLC-DAD analysis identified higher HT concentration (1900 ppm) in the supercritical extracts at the highest temperature. Consequently, at 373 K, the total phenol content and the antioxidant capacity of the extracts was uppermost. No HT was found in the n-hexane extracts.Item The Hansen theory to choose the best cosolvent for supercritical CO2 extraction of β-carotene from Dunaliella salina(The Journal of Supercritical Fluids, 2019) Tirado Armesto, Diego Felipe; Calvo Garrido, María LourdesThe Hansen solubility theory was used to predict the best cosolvent for supercritical carbon dioxide (sc-CO2) to achieve the selective extraction of β-carotene from Dunaliella salina. Among four organic cosolvents, ethanol was predicted to be the best based on minima Ra values. The predictions were validated through equilibrium data and extraction curves from the microalgae. The addition of ethanol reduced the bubble pressures, and therefore increased the solubility of the β-carotene. With 5% mass fraction, at 318.15 K and 20 MPa, the extraction yield was 25 g carotenoids kg microalgae−1, much more than in pure sc-CO2 (6 g).Item Prediction of the best cosolvents to solubilise fatty acids in supercritical CO2 using the Hansen solubility theory(Chemical Engineering Science, 2018) Tirado Armesto, Diego Felipe; Tenorio, María José; Cabañas Poveda, Albertina; Calvo Garrido, María LourdesCosolvents are employed to improve the extraction efficiency and modify the selectivity of the main solvent. However, choosing a proper cosolvent in supercritical extraction is an arduous task. This study aimed to predict the best cosolvents for the supercritical CO2 extraction of oleic and linoleic acids using the Hansen solubility theory. Calculations were performed for eight organic cosolvents used in food and pharmaceutical production. The best cosolvents for the solubilization of both fatty acids were short-chain alcohols, ethanol and methanol. The predictions were validated with bubble pressures of the mixtures with a 0.003 fatty acid molar fraction at temperatures of 313.2 K and 323.2 K. The experimental results agreed with the predictions. The effect of pressure was well predicted via the direct relationship between pressure and the solvent density. However, the impact of temperature was not properly foreseen because the variation of solute vapour pressure was not considered. The Hansen theory predicted that the miscibility enhancement of the solute in the supercritical mixture is maximum at low pressures and low cosolvent concentrations, as was experimentally confirmed.Item The encapsulation of hydroxytyrosol-rich olive oil in Eudraguard® protect via supercritical fluid extraction of emulsions(Journal of Food Engineering, 2021) Tirado, Diego ; Latini, Angela; Calvo Garrido, María LourdesThe SFEE technology was used to micronize the food-approved-biopolymer Eudraguard® protect. After setting the ratio of emulsion phases to 20:80 ethyl acetate:water, higher surfactant (0.1–10.0%) and lower polymer (1–10%) concentrations reduced the size of the particles. By halving the stirring speed to 1250 rpm during the homogenization of the emulsion, larger particles were formed. All these manipulations allowed the creation of particles ranging from 10 nm to 200 nm. A higher viscosity of the organic phase, achieved with 2% vitamin E, increased the particle size to 300 nm. Afterwards, SFEE was used to encapsulate hydroxytyrosol-rich olive oil (HT-oil), obtained from alperujo, in Eudraguard® protect for its preservation. Spherical non-aggregate particles were formed with an average of 230 nm. High degrees of encapsulation were possible (up to 99%) resulting in loadings of HT-oil in the obtained particles of 39% with 0.7 mg HT per g of particle.Item Sterilization of Biological Weapons in Technical Clothing and Sensitive Material by High-Pressure CO2 and Water(Industrial & Engineering Chemistry Research, 2018) Calvo Garrido, Lourdes; Casas Huertas, Javier; Calvo Garrido, María LourdesThis work explores the effectiveness of highpressure CO2 on inactivation of Bacillus thuringiensis spores as a surrogate of B. anthracis spores (anthrax). The investigation was done in combatant equipment and several electronic devices. It was possible to sterilize this sensitive material by the environmentally friendly mixture formed by high-pressure CO2 and water. The presence of water in mass proportions ranging from 20 to 30% relative to the material was essential. However, it was continuously introduced in small amounts (<4% in relation to CO2), entrained by the CO2, so as not to have an adverse impact on materials. A low external pH enhanced the inactivation. Therefore, by using CO2 mixed with water acidified with citric acid to 3.3, the spores were killed at only 45 °C. The much less aggressive conditions of the treatment allowed preservation of the quality of the technical fabrics and the functionality of the electronic devices.Item The parameters that affect the supercritical extraction OF 2,4,6- trichloroanisol from cork(Journal of Supercritical Fluids, 2018) Viguera Sáenz, Miguel; Prieto, C.; Casas, E.; Cabañas Poveda, Albertina; Calvo Garrido, Lourdes; Calvo Garrido, María LourdesThe contamination of wine by 2,4,6-trichloroanisol (TCA) derived from the cork stopper is a huge problem for the wine industry. This work shows the results of TCA extraction using supercritical CO2. Cork granules (6% moisture) were placed forming a fixed bed within a high-pressure vessel. The CO2 was made to continuously flow over this. The TCA removal was compared at different operating conditions (pressure, temperature, flow rate or extraction time). TCA removal was not possible in dried cork. Density had a positive impact in TCA removal due to the solvent capacity increase. An increase in the supercritical fluid temperature over 60 °C impaired the TCA extraction. High residence times benefited the extraction. At high CO2 density of 585 kg m−3 , TCA elimination below the detection level was achieved in 8 min residence time. This required relatively low solvent to cork mass ratios (43 kg CO2 kg−1 ).Item Deposition of Au nanoparticles into mesoporous SiO2 SBA-15(The Journal of Supercritical Fluids, 2022) Huerta, Andrea; Torralvo Fernández, María Josefa; Tenorio, María José; Pérez Velilla, Eduardo; Bermúdez, Jonathan; Calvo Garrido, María Lourdes; Cabañas Poveda, AlbertinaAu/SiO2 SBA-15 materials were prepared using supercritical CO2 (scCO2) and by wet impregnation. First, SiO2 SBA-15 was functionalized with thiol groups at different grafting densities using 3-(Mercaptopropyl)trimethoxysilane dissolved in scCO2. The support was then impregnated with HAuCl4·3H2O in scCO2 modified with EtOH. Wet impregnation of the supports with HAuCl4·3H2O in ethanol was also performed. Materials were calcined at 500 °C to remove the organic matter and promote particle growth. Materials prepared on the highest thiol grafting density support showed Au NP between 2.5 and 5 nm homogeneously distributed within the mesopores. Slightly larger Au NPs were obtained in scCO2 modified with EtOH. Materials prepared on the low thiol grafting density support showed a bimodal particle size distribution with particles up to 7 nm located inside the mesopores and larger ones of 10–20 nm on the external surface. A possible reaction mechanism was proposed. These materials can be used in catalysis, sensing and biomedicine.