| 1. |
- Gil-Ramirez, Alicia, et al.
(författare)
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Data on saponins, xylan and cellulose yield obtained from quinoa stalks after pressurized hot water extraction
- 2018
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Ingår i: Data in Brief. - : Elsevier BV. - 2352-3409. ; 20, s. 289-292
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Tidskriftsartikel (refereegranskat)abstract
- The data we present below are linked to our research paper “Integrated process for sequential extraction of saponins, xylan and cellulose from quinoa stalks (Chenopodium quinoa Willd.)” (Gil-Ramírez et al., 2018) [1]. The objective is to provide supplementary information in order to facilitate the comprehension of the central composite experimental design (rotatable 22) used in the integrated process of extractions. Two factors, temperature and time of extraction are considered in the design. The responses are the yield of saponin, xylan and cellulose. First, the desirable linear regression obtained by the observed vs. predicted yields plot for each variable response confirm the validation of the model (Fig. 1). Second, the data presented here through Standardized Pareto Charts (Fig. 2), provides information about the effect of the time and temperature, as well as their interactions, in the yield of saponins, xylan and cellulose obtained in an integrated sequential extraction.
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| 2. |
- Gil-Ramirez, Alicia, et al.
(författare)
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Efficient methodology for the extraction and analysis of lipids from porcine pulmonary artery by supercritical fluid chromatography coupled to mass spectrometry
- 2019
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Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673. ; 1592, s. 173-182
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Tidskriftsartikel (refereegranskat)abstract
- Pulmonary artery grafts are needed as cardiovascular bioprosthetics. For successful tissue recellularization after transplantation, lipids have to be removed from the donor artery. Developing a selective process to remove lipids without damaging the extracellular matrix greatly depends on knowing the amount and type of lipid compounds in the specific tissue. Here we present an efficient methodology for the study of lipids present in porcine pulmonary arteries. The performance of six extraction methods to recover lipids from artery was evaluated. For this purpose, a supercritical fluid chromatography method coupled to quadrupole time-of-flight mass spectrometry detection (UHPSFC/QTOF-MS) was adapted. The method enabled separation of lipids of a wide range of polarity according to lipid class in less than 7 min. One dichloromethane-based extraction method was shown to be the most efficient one for the recovery of lipids from pulmonary artery. However, one MTBE-based extraction method was able to show the highest fatty acid extraction yields (to the expense of longer extraction times). Lipids were relative quantified according to class, and the major species within each class were identified. Triacylglycerols and glycerophospholipids were the most abundant classes, followed by sphingomyelins, monoacylglycerols and fatty acyls. The matrix effect exerted no interference on the analytical method, except for some few combinations of extraction method and lipid class. These results are of relevance for lipidomic studies from solid tissue, in particular for studies on pulmonary and cardiovascular diseases. Finally, our work sets the basis for the further development of a selective processes to remove lipids from pulmonary artery without damaging the tissue prior to transplantation.
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| 3. |
- Gil-Ramírez, Alicia, et al.
(författare)
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Pressurized carbon dioxide as a potential tool for decellularization of pulmonary arteries for transplant purposes
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Vascular bio-scaffolds produced from decellularized tissue offer a promising material for treatment of several types of cardiovascular diseases. These materials have the potential to maintain the functional properties of the extracellular matrix (ECM), and allow for growth and remodeling in vivo. The most commonly used methods for decellularization are based on chemicals and enzymes combinations, which often damage the ECM and cause cytotoxic effects in vivo. Mild methods involving pressurized CO2-ethanol (EtOH)-based fluids, in a supercritical or near supercritical state, have been studied for decellularization of cardiovascular tissue, but results are controversial. Moreover, data are lacking on the amount and type of lipids remaining in the tissue. Here we show that pressurized CO2-EtOH-H2O fluids (average molar composition, ΧCO2 0.91) yielded close to complete removal of lipids from porcine pulmonary arteries, including a notably decrease of pro-inflammatory fatty acids. Pressurized CO2-limonene fluids (ΧCO2 0.88) and neat supercritical CO2 (scCO2) achieved the removal of 90% of triacylglycerides. Moreover, treatment of tissue with pressurized CO2-limonene followed by enzyme treatment, resulted in efficient DNA removal. The structure of elastic fibers was preserved after pressurized treatment, regardless solvent composition. In conclusion, pressurized CO2-ethanol fluids offer an efficient tool for delipidation in bio-scaffold production, while pressurized CO2-limonene fluids facilitate subsequent enzymatic removal of DNA.
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| 4. |
- Gil-Ramírez, Alicia, et al.
(författare)
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Purification of Natural Products by Selective Precipitation Using Supercritical/Gas Antisolvent Techniques (SAS/GAS)
- 2021
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Ingår i: Separation and Purification Reviews. - : Informa UK Limited. - 1542-2119 .- 1542-2127. ; 50:1, s. 32-52
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Forskningsöversikt (refereegranskat)abstract
- Supercritical fluids offer considerable advantages for the isolation of natural products. Supercritical fluids can be used as antisolvents to precipitate selectively target compounds from a mixture and to remove impurities by the Supercritical Antisolvent technique (SAS). The present decade has experienced a considerable increase in the number of publications that apply this technique to natural extracts, especially for the isolation of polyphenols and carotenoids from plants and microalgae. However, the lack of a clear terminology and purpose adds confusion to the topic. The proposed review aims at defining a research field that consists in applying SAS to natural extracts for the purification of target compounds. To do so, we trace back the origin of the field, discuss the different terminology used to refer to such processes, and suggest appropriate terms for the process and for reported results. This work explores the scope of the topic by compiling all works published to date from a scattered literature, using all possible process terminologies for the search. The information given aims to highlight the most promising applications explored so far and possibly inspire further research.
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| 5. |
- Gil-Ramírez, Alicia, et al.
(författare)
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Strengths and weaknesses of the aniline-blue method used to test mushroom (1→3)-β-D-glucans obtained by microwave-assisted extractions
- 2019
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617. ; 217, s. 135-143
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Tidskriftsartikel (refereegranskat)abstract
- The parameters to extract polysaccharide-enriched fractions (PEF) from mushrooms using MAE (microwave-assisted extraction) were adjusted following a full factorial 3 2 experimental design. The highest yield and total carbohydrate values, using Lentinula edodes as model mushroom, were obtained at 180 °C and 30 min. Several mushroom species were submitted to MAE and their PEF yields ranged between 12.1–44.2%. (1→3)-β-Glucans determination using a conventional fluorimetric method changed depending on the standard utilized. NMR analyses of PEF indicated that the presence of other polysaccharides in the extracts or their specific folding, might impair the proper determination of (1→3) linkages by the fluorophore. Mushrooms from Cantharellales order contained (1→3)-β-glucans but they were not detected with the fluorimetric method. Therefore, although the method (after adjustments) was sensitive enough to detect their presence in many mushroom extracts, it cannot be used for all species and it is also not recommended for quantitative determinations.
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| 6. |
- Ramirez, Alicia Gil, et al.
(författare)
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Integrated process for sequential extraction of saponins, xylan and cellulose from quinoa stalks (Chenopodium quinoa Willd.)
- 2018
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Ingår i: Industrial Crops and Products. - : Elsevier BV. - 0926-6690. ; 121, s. 54-65
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Tidskriftsartikel (refereegranskat)abstract
- World quinoa production is increasing due its high nutritional value. As a consequence, large quantities of stalks accumulate as unused byproducts. Here, we verify the presence of saponins in the stalks and present a biorefinery approach with quinoa stalks as feedstock, using an integrated processing scheme to separate saponins, xylan and cellulose. Saponins were extracted using pressurized hot water extraction (PHWE), optimized by a central composite experimental design (rotatable 22) with temperature and extraction time as factors. Xylan was extracted from the residual solid material after PHWE by an alkaline method using 0.5 M NaOH at 80 °C. Cellulose was purified from the remaining residuals using acetic and nitric acid at 120 °C, which resulted in recovery of white cotton-like cellulose, showing no need of further bleaching. The saponin yield was significantly increased at temperatures exceeding 110 °C, with highest amounts obtained at 195 °C (15.4 mg/g raw material). The yield in the following xylan extraction (maximum 120 mg/g raw material) was however significantly reduced when preceded by PHWE above 110 °C, indicating degradation of the polymer. Cellulose recovery (maximum 296 mg/g raw material) was less affected by variations in temperature and time in the preceding PHWE. The results obtained shows that tuning between saponin and xylan extraction is critical. This approach is foreseen to be applicable to the valorisation of residual fiber-rich biomass from various types of crops, besides quinoa.
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