LATESC – Laboratório de Termodinâmica e Tecnologia Supercrítica
  • CALL OF ABSTRACTS: VI Iberoamerican Conference on Supercritical Fluids

    Publicado em 20/05/2023 às 08:40 PM

    Call of abstracts is now open!

    The abstract submission is open until June 15th, 2023. 

    Submit your abstract.

  • Encapsulation of methionine in ethyl cellulose by supercritical fluids technique

    Publicado em 20/05/2023 às 08:34 PM

    Thuany Naiara Silva Laurintino, P. V. de Oliveira, J. L. Dias, Thaíris K.S. Laurintino, E. Rebelatto, J. V. Oliveira, A. Bolzan

    August 2023

    Methionine is an amino acid of great importance for lactating dairy cows, as it directly affects the quality and quantity of milk these animals produce. The main objective of this work was to investigate the encapsulation of methionine in ethyl cellulose with ethanol and acetic acid as a mixture solvent using the GAS technique. A central composite design 23 with three central points was used to evaluate the influence of methionine/polymer ratio (1:3, 1:2, and 1:1), temperature (308, 313, and 318 K), and pressure (10, 12, and 14 MPa) in terms of particle diameter, morphology of the particles, percentage of encapsulated material, encapsulation efficiency, and yield of precipitation. The release behavior of the particles precipitated was evaluated in two fluids – simulated gastric and simulated intestinal fluids. Encapsulation efficiencies as high as 99.72 % were obtained, for which the system methionine/polymer ratio showed a negative effect (95 % confidence level).

  • High-pressure phase equilibrium data for the ternary and quaternary systems containing carbon dioxide, globalide, ε-caprolactone dichloromethane

    Publicado em 20/05/2023 às 08:23 PM

    Anderson C Dutra, Diego A Mayer, Adriano Silva, Evertan A Rebelatto, J Vladimir Oliveira

    July 2023

    Polymers, both natural and synthetic, are present in many areas of modern society. The majority of these polymers, however, are made from petroleum-derived monomers, a non-renewable source that produces pollutants. In this way, it is necessary to search for biodegradable polymers that do not generate pollutants both in production and disposal. The use of supercritical carbon dioxide (scCO2), replacing organic solvents, has shown to be a green alternative to traditional polymerization processes. This work reports experimental phase equilibrium data for the ternary system involving carbon dioxide, globalide and ε-caprolactone and quaternary system containing carbon dioxide, dichloromethane, globalide and ε-caprolactone, which are fundamental information to conduct polymerization reactions in supercritical carbon dioxide medium. The experiments were performed using a variable-volume view cell over the temperature range from 313.15 to 343.15 K, and different molar fractions of carbon dioxide in relation to monomers (globalide + ε-caprolactone) for ternary system and different mass ratios of dichloromethane to monomers (globalide + ε-caprolactone) (0.5:1, 1:1) for quaternary system. Phase transitions of vapor-liquid equilibrium at the bubble point (VLE-PB) and dew point (VLE-DP) were observed. The mass ratio of 1:1 (globalide to caprolactone) was kept constant for all systems. The PR-vdW2 model with a global temperature fitting approach was employed to predict the phase equilibrium behavior for the ternary and quaternary systems and the thermodynamic model was able to properly correlate the phase equilibrium transition.

  • Pressurized liquid extraction as an eco-friendly approach to recover anthocyanin from black rice bran

    Publicado em 20/05/2023 às 08:21 PM

    Eduardo Leonarski, Mayara Kuasnei, Paulo Alexandre Durant Moraes, Karina Cesca, Débora de Oliveira, Acácio AF Zielinski

    June 2023

    This study aimed to recover the anthocyanin-rich extract from black rice bran by pressurized liquid extraction (PLE) and compare with the conventional process (heating-stirring extraction – HSE). PLE performs fast and efficiently and results in high yields in less time and less solvent, being considered eco-friendly. The extracts were characterized for thermal and light stabilities, cytotoxicity, antitumoral activity, and cytoprotective effect. Optimum PLE conditions were: 55 °C, a flow rate of 5 mL/min, and solution ethanol:citric acid 0.1 mol/L (50:50, v/v). PLE recovered about 80% of total anthocyanins (2.33 mg/C3GE g), while HSE recovered 46% (1.17 mg/C3GE g). Cyanidin-3-O-glucoside (C3G) was identified (m/z 449) and quantified, 1.63 mg/g for PLE and 1.07 mg/g for HSE. Both anthocyanin-rich extracts in low temperature showed high thermostability, did not present cytotoxicity (normal fibroblast L929 cells), and showed cytoprotection of L929 cells when subjected to oxidative stress with H2O2. Overall, the anthocyanin-rich extracts obtained by PLE showed potential to be applied as natural colorants and possibly to improve wound healing.

  • Black rice and its by-products: anthocyanin-rich extracts and their biological potential

    Publicado em 20/05/2023 às 08:19 PM

    Eduardo Leonarski, Mayara Kuasnei, Karina Cesca, Débora de Oliveira, Acácio AF Zielinski

    May 2023

    Recently, growing demand for products enriched with natural compounds that support human health has been observed. Black rice, its by-products, and residues are known to have in their composition a large amount of these compounds with biological potential, mainly anthocyanins. These compounds have reported effects on anti-obesity, antidiabetic, antimicrobial, anticancer, neuroprotective, and cardiovascular disease. Therefore, the extract from black rice or its by-products have great potential for application as ingredients in functional foods, supplements, or pharmacological formulations. This overview summarizes the methods employed for the extraction of anthocyanins from both black rice and its by-products. In addition, trends in applications of these extracts are also evaluated regarding their biological potential. Commonly, the extraction methods used to recover anthocyanins are conventional (maceration) and some emerging technologies (Ultrasound-Assisted Extraction – UAE, and Microwave-Assisted Extraction – MAE). Anthocyanin-rich extracts from black rice have presented a biological potential for human health. In vitro and in vivo assays (in mice) showed these compounds mainly with anti-cancer properties. However, more clinical trials are still needed to prove these potential biological effects. Extracts from black rice and its by-products have great potential in applying functional products with beneficial characteristics to humans and reducing agro-industrial residues.

  • High-pressure phase equilibrium data of carbon dioxide/food-relevant systems (2011-2022): experimental methods, multiphase behavior, thermodynamic modeling, and applications

    Publicado em 20/05/2023 às 08:13 PM

    Clóvis A Balbinot Filho, L Dias Jônatas, Evertan A Rebelatto, Marcelo Lanza

    May 2023

    High-pressure phase equilibrium data involving food-type substances and pure or cosolvent-modified pressurized carbon dioxide (CO2) published in the last decade are reviewed. Experimental data regarding binary, ternary, and multicomponent systems studied at 293-373 K and pressures up to 55 MPa are compiled. CO2/lipid-like substances (fatty acids, esters, triacylglycerols), essential oils, and their components are the most studied food systems, followed by systems containing biopolymers. The Vapor-Liquid Equilibrium is the most observed fluid-fluid transition at experimental conditions. The cosolvent effect of organic solvents in removing immiscibility gaps like the Vapor-Liquid-Liquid and the Liquid-Liquid boundaries, the antisolvent role of CO2 to some solutes, and its plasticizing effect on polymers and solid lipids are also highlighted in the context of solid-fluid equilibrium. The Peng and Robinson Equation of State coupled with the Van der Waals type mixing rules is still the main thermodynamic model applied for modeling phase equilibrium of these systems, despite some correlative limitations regarding multicomponent mixtures containing polar molecules. Combining classical Equations of State with the associative term and predictive models as Group Contribution methods is a reliable tool to improve the modeling of systems with complex phase behaviors. Fluid phase immiscibility regions and experimental conditions that favor the presence of a solid phase are mainly useful to set the appropriate operating point based on phase diagrams and the observed equilibria. For many applications, phase equilibrium is relevant in processing food-type substances destined for food or food-related applications and human consumption by processes employing CO2 as an extraction solvent, a fractionating, dispersant, precipitative, or atomizing (antisolvent) agent, or as a reaction medium for biocatalysis.

  • Solubility of Food-Relevant Substances in Pure and Modified Supercritical Carbon Dioxide: Experimental Data (2011–Present), Modeling, and Related Applications

    Publicado em 20/05/2023 às 08:11 PM

    Clóvis A Balbinot Filho, Jônatas L Dias, Evertan A Rebelatto, Marcelo Lanza

    May 2023

    For many high-pressure processes employing pressurized fluids, such as supercritical fluid extraction (SFE) of natural matrices with supercritical carbon dioxide (scCO2), CO2 plays a central role as a solvent, solubilizing agent, or medium for extracting and processing diverse food-type substances, in which the knowledge on the solubility behavior of multiple compounds at the varying process conditions is essential in the process design, but not completely understood. High-pressure solubility data in pure scCO2 or cosolvent-modified CO2 of distinct types of organic compounds found in or related to food (mainly vegetable oils, essential oils, carotenoids, phenolics, and vitamins) published in the last decade were reviewed, encompassing temperatures of 298–373 K and pressures up to 95 MPa. Crossover phenomena, solubility enhancements in cosolvent systems or those containing a co-solute, and the antisolvent feature of CO2 are also discussed. Current models for the correlation of solubility data by semi-empirical and thermodynamic models are compared, and the limitations of each class of models are highlighted. Lipid-soluble substances (fatty acid esters, fatty acids, and essential oils) are the most CO2-soluble food-type substances in contrast to polar and complex polyphenols and carotenoids. The investigated solutes can be obtained by SFE, separated by fractionation using scCO2, or applied to enzymatic reactions and particle formation processes. It was concluded based on recent applications that improved SFE, effective separation factors for supercritical fractionation, better solubilization of reactive systems, and supersaturation conditions to obtain micronized particles could be established based on the solubility behavior of dissolved solutes in the supercritical media at high pressures.


  • High presure phase behavior and thermodynamic modelling of the carbon dioxide + chloroform + globalide system

    Publicado em 20/05/2023 às 08:08 PM

    Davi Gustavo Lisboa Girardi, Aurora Lorini Letsch, Evertan Antonio Rebelatto, Diego Alex Mayer, José Vladimir de Oliveira

    April 2023

    The high-pressure phase behavior of the ternary system constituted by carbon dioxide + globalide + chloroform was studied. Experiments were conducted applying the synthetic-visual method in a variable-volume view cell at a mass ratios of globalide to chloroform of 0.5:1, 1:1, and 2:1, over a temperature range from 313.15 to 343.15 K, and pressures from 5.17 to 20.25 MPa. Phase transitions of vapor–liquid bubble point (VLE-BP), vapor–liquid dew point (VLE-DP), liquid-liquid (LLE), and vapor–liquid-liquid (VLLE) type were observed. Furthermore, through the P-w diagram, the phase behavior of the ternary system in chloroform free-basis was analyzed between 0.4250 to 0.9735 of carbon dioxide mass composition. It has been observed that high quantities of chloroform lead to lower transition pressures. Moreover, PT-diagrams efficiently displayed that higher pressures are necessary to achieve a single phase medium as temperature rises, which characterize LCST behavior. PR-vdW2 model was used to estimate binary interaction parameters. Additionaly, the ternary system was compared with binary systems avaiable in the literature. The data presented in this work provides necessary information for the optimization and improvement of poly(globalide) synthesis in supercritical media.

  • Optimization of the subcritical water extraction of sulfated flavonoids from Flaveria bidentis

    Publicado em 20/05/2023 às 08:03 PM

    Paulina Falletti, María Fernanda Barrera Vázquez, Luiz Gustavo Gonçalves Rodrigues, Pedro Henrique Santos, Marcelo Lanza, Jose Luis Cabrera, Raquel Evangelina Martini, Laura Raquel Comini

    April 2023

    Flaveria bidentis, an invasive plant, contains sulfated flavonoids (SFs) with therapeutic potential; therefore, their extraction would add value to the plant residues generated during its weeding. This work reports the optimized obtaining of these SFs, by means of subcritical water extraction (SWE). The combined effects of Flow rate, Temperature, and Particle size were investigated via response surface methodology involving the Doehlert experimental design. The optimal extraction conditions were: leaves: Flow rate = 2.86 mL/min, Temperature = 101.2 °C and Particle size = 420–< 1190 µm; flowers: Flow rate = 4.29 mL/min, Temperature = 147.7 °C and Particle size = 0 – < 420 µm. Under these conditions, 39.43 and 7.5 mg of totals SF/100 g of leaves and flowers were recovered, respectively. Likewise, we could demonstrate that SWE showed an improved efficiency the extraction of the SFs under study of more than twice as high compared to the conventional method (reflux).

  • Conventional lignin functionalization for polyurethane applications and a future vision in the use of enzymes as an alternative method

    Publicado em 20/05/2023 às 08:01 PM

    Thayli Ramires Araujo, D. Bresolin, D. de Oliveira, C. Sayer, Pedro Henrique Hermes de Araújo, J. Vladimir de Oliveira

    April 2023

    The valorization of lignin in polyurethane products allows biorefineries and paper industries to use this biomass with some added value and not waste most of it in combustion to generate energy. Lignin is known as the second most abundant natural polymer in the world. It comprises a complex structure formed by covalent bonds between phenylpropanoid alcohols, making its composition heterogeneous. In recent decades, lignin has been exploited as a raw material in the synthesis of polyurethanes to replace petrochemical derivatives. Despite its promising characteristics in polyurethane products, lignin has limitations in its use due to its highly complex and cross-linked molecular structure. To overcome this challenge, methods have been developed to make lignin more reactive, facilitating its use in various polymeric processes. Among the methods is chemical modification and fragmentation of lignin. Although research has advanced concerning the depolymerization of lignin through chemical catalysis and enzymatic catalysis synthesis, research only focuses on the process of functionalizing lignin for its application in various areas, however, these explored methods are considered as pretreatment of biomass, adding another step in the polyurethane synthesis. Scientific efforts should also be directed to studies on the production of lignopolyols derived from enzymatic catalysis to produce polyurethanes. Thus, this review addresses conventional methods used in the chemical modification of lignin and ways of application, including polyurethane products that can be developed based on lignin, briefly addresses studies related to enzyme vs. lignin, and points out a gap that exists in the literature on enzymatic catalysis in the production of lignopolyols applicable to PUs.