Search

Your search keyword '"Vaca Garcia, C"' showing total 15 results
Start Over Author "Vaca Garcia, C" Publication Year Range Last 10 years
15 results on '"Vaca Garcia, C"'

2. Extruded poly(ethylene-co-vinyl alcohol) composite films containing biopolymers isolated from municipal biowaste

Author

Nistico', R, Evon, P, Labonne, L, Vaca Medina, G, Montoneri, E, Francavilla, M, Vaca Garcia, C, Magnacca, G, Franzoso, F, Negre, M, NISTICO', ROBERTO, Evon, P., Labonne, L., Vaca Medina, G., Montoneri, E., Francavilla, M., Vaca Garcia, C., Magnacca, G., Franzoso, F., Negre, M., Nistico', R, Evon, P, Labonne, L, Vaca Medina, G, Montoneri, E, Francavilla, M, Vaca Garcia, C, Magnacca, G, Franzoso, F, Negre, M, NISTICO', ROBERTO, Evon, P., Labonne, L., Vaca Medina, G., Montoneri, E., Francavilla, M., Vaca Garcia, C., Magnacca, G., Franzoso, F., and Negre, M.

Abstract

Single-screw extrusion allows obtaining composite films containing poly(ethylene-co-vinyl alcohol), hereinafter EVOH, and water-soluble lignin-like biopolymers (SLP) isolated from the alkaline hydrolysate of two materials sampled from an urban waste treatment plant. During extrusion, a condensation reaction occurs between the EVOH and SLP. The products are heterogeneous. They contain a mix of EVOH-SLP copolymers with different composition and solubility properties. The films were characterized for tensile strength and water sorption properties. Young modulus and strain at break, respectively, were 2.8 GPa and 14% for neat EVOH vs. 2.1-0.9 GPa and 17–4% for the blends containing 2–15% SLP, with values decreasing upon increasing the % SLP. The blends were more hydrophilic than neat EVOH; their water sorption capacity was found to increase upon increasing the SLP content. Compared to previously reported similar blends obtained by twin-screw extrusion and solvent casting, the data for the single-screw extruded films allows discussing several aspects connected to the valorisation of blends obtained from fossil and biowaste sourced polymers.

Published
2016

3. Post-harvest tomato plants and urban food wastes for manufacturing plastic films

Author

Nistico', R, Evon, P, Labonne, L, Vaca Medina, G, Montoneri, E, Vaca Garcia, C, Negre, M, NISTICO', ROBERTO, Evon, Philippe, Labonne, Laurent, Vaca Medina, Guadalupe, Montoneri, Enzo, Vaca Garcia, Carlos, Negre, Michele, Nistico', R, Evon, P, Labonne, L, Vaca Medina, G, Montoneri, E, Vaca Garcia, C, Negre, M, NISTICO', ROBERTO, Evon, Philippe, Labonne, Laurent, Vaca Medina, Guadalupe, Montoneri, Enzo, Vaca Garcia, Carlos, and Negre, Michele

Abstract

Poly(vinyl alcohol-co-ethylene) was compounded with 2e10% post-harvest tomato (PHT) plant powder and processed by single-screw extrusion to yield composite films. Upon increasing the filler content, the values of the mechanical properties indicators were found to decrease as follows: Young's modulus from 1797 to 750 MPa, stress at yield from 36 to 15 MPa, maximal stress from 39 to 15 MPa, stress at break from 35 to 14 MPa, and strain at break from 6.6 to 4.3%. The results are discussed in comparison with other composite films containing poly(vinyl alcohol-co-ethylene) and water soluble biopolymers obtained by alkaline hydrolysis of fermented municipal biowastes, and with other commercial materials, such as starch based and low density polyethylene mulch films. Depending on the intended application, the post-harvest tomato blend films may be competitive for cost, performance and sustainability.

Published
2017

4. Thermopressed binderless fiberboards from post-harvest tomato and maize plants

Author

Evon, P, Labonne, L, Nistico', R, Montoneri, E, Vaca Garcia, C, Nègre, M, Evon, P, Labonne, L, Nistico', R, Montoneri, E, Vaca Garcia, C, and Nègre, M

Abstract

Post-harvest tomato plants were used to manufacture fireboards by thermopressing. Four plant materials were investigated: exhausted tomato plants ground to 5-10 mm (PHTr), tomato (PHT) and maize (PHM) plants ground to <0.5 mm, composted tomato plants (CPHT). These materials had significantly different chemical composition, which significantly influenced the fireboards mechanical properties. The PHM fireboards containing the highest amount hemicellulose and water soluble sugars, and the lowest minerals‘ amount, performed best. The data allow estimating the role of each plant proximate in determining board mechanical behavior. Moreover, the findings of the work prospect a desirable integration of municipal and agriculture biowastes as a step forward toward the valorization of renewable organic matter and the realization of the zero waste objective.

Published
2017

6. Extruded versus solvent cast blends of poly(vinyl alcohol-co-ethylene) and biopolymers isolated from municipal biowaste

Author

Franzoso, F, Vaca Garcia, C, Roully, A, Evon, P, Montoneri, E, Persico, P, Mendichi, R, Nistico', R, Francavilla, M, Franzoso, Flavia, Vaca Garcia, Carlos, Roully, Antoine, Evon, Philippe, Montoneri, Enzo, Persico, Paola, Mendichi, Raniero, NISTICO', ROBERTO, Francavilla, Matteo, Franzoso, F, Vaca Garcia, C, Roully, A, Evon, P, Montoneri, E, Persico, P, Mendichi, R, Nistico', R, Francavilla, M, Franzoso, Flavia, Vaca Garcia, Carlos, Roully, Antoine, Evon, Philippe, Montoneri, Enzo, Persico, Paola, Mendichi, Raniero, NISTICO', ROBERTO, and Francavilla, Matteo

Abstract

Water-soluble biopolymers (SBO) were isolated from the alkaline hydrolysate of two materials sampled from an urban waste treatment plant; that is, an anaerobic fermentation digestate and a compost. The digestate biopolymers contained more lipophilic and aliphatic C, and less acidic functional groups than the compost biopolymers. The SBO were blended with poly (vinyl alcohol-co-ethylene), hereinafter EVOH. The blends were extruded and characterized by FTIR spectroscopy, size exclusion chromatography (SEC)– multi angle static light scattering (MALS) analysis, and for their thermal, rheological, and mechanical properties. The blends behavior depended on the type of SBO and its relative content. Evidence was obtained for a condensation reaction occurring between the EVOH and SBO. The best results were obtained with the blends containing up to 10% SBO isolated from the biowaste anaerobic digestate. Compared with the neat EVOH, these blends exhibited lower melt viscosity and no significant or great difference in mechanical properties. The results on the extrudates, compared with those previously obtained on the same blends obtained by solvent casting, indicate that the blends properties depend strongly also on the processing technology.

Published
2016

7. Post-harvest tomato plants and urban food wastes for manufacturing plastic films

Author

Enzo Montoneri, Guadalupe Vaca-Medina, Carlos Vaca-Garcia, Michèle Negre, Philippe Evon, Roberto Nisticò, Laurent Labonne, Dipartimento di Scienza Applicata e Tecnologia DISAT, Politecnico di Torino = Polytechnic of Turin (Polito), Chimie Agro-Industrielle (CAI), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National de la Recherche Agronomique (INRA), Biowaste Processing, Dipartimento di Scienze Agrarie, Forestali e Alimentari, Università degli studi di Torino (UNITO), Politecnico di Torino [Torino] (Polito), Institut National de la Recherche Agronomique (INRA)-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Biowaste Processing (ITALY), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Università degli studi di Torino - UNITO (ITALY), Politecnico di Torino (ITALY), Laboratoire de Chimie Agro-Industrielle - LCA (Toulouse, France), Institut National Polytechnique de Toulouse - INPT (FRANCE), Nistico', R, Evon, P, Labonne, L, Vaca Medina, G, Montoneri, E, Vaca Garcia, C, and Negre, M

Subjects
Agronomie, Starch, Strategy and Management, [SDV]Life Sciences [q-bio], Young's modulus, biopolymers, 02 engineering and technology, 010501 environmental sciences, municipal food wastes, gestion des déchets agricoles, 01 natural sciences, Industrial and Manufacturing Engineering, agricultural waste management, chemistry.chemical_compound, Biopolymers, Municipal food wastes, biopolymer, 11. Sustainability, Municipal food waste, Food science, post-harvest tomato plants, Alkaline hydrolysis, General Environmental Science, Waste management, Extrusion, food and beverages, 021001 nanoscience & nanotechnology, composite material, blend films, Low-density polyethylene, symbols, Biomaterials Biopolymers Blend films Extrusion Municipal food wastes Post-harvest tomato plants, 0210 nano-technology, biomaterials, Vinyl alcohol, CHIM/03 - CHIMICA GENERALE ED INORGANICA, Yield (engineering), Materials science, post récolte, Plastic film, valorisation des résidus, Biomaterials, symbols.namesake, Blend films, Post-harvest tomato plants, 0105 earth and related environmental sciences, Renewable Energy, Sustainability and the Environment, Biomaterial, Amélioration des plantes, extrusion, chemistry, matériau composite, biopolymère, biomatériau, Post-harvest tomato plant, Blend film
Abstract

Poly(vinyl alcohol- co -ethylene) was compounded with 2–10% post-harvest tomato (PHT) plant powder and processed by single-screw extrusion to yield composite films. Upon increasing the filler content, the values of the mechanical properties indicators were found to decrease as follows: Young's modulus from 1797 to 750 MPa, stress at yield from 36 to 15 MPa, maximal stress from 39 to 15 MPa, stress at break from 35 to 14 MPa, and strain at break from 6.6 to 4.3%. The results are discussed in comparison with other composite films containing poly(vinyl alcohol- co -ethylene) and water soluble biopolymers obtained by alkaline hydrolysis of fermented municipal biowastes, and with other commercial materials, such as starch based and low density polyethylene mulch films. Depending on the intended application, the post-harvest tomato blend films may be competitive for cost, performance and sustainability.

Published
2017

8. Thermopressed binderless fiberboards from post-harvest tomato and maize plants

Author

Enzo Montoneri, Carlos Vaca-Garcia, Philippe Evon, Roberto Nisticò, Michèle Negre, Laurent Labonne, Montoneri, Enzo, Chimie Agro-Industrielle (CAI), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National de la Recherche Agronomique (INRA), Université Fédérale Toulouse Midi-Pyrénées, Universita di Torino, Biowaste Processing, COST-European Cooperation in Science and Technology EUBis Action TD1203 [COST-STSM-TD1203- 26977], Biowaste Processing (ITALY), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Università degli studi di Torino - UNITO (ITALY), Evon, P, Labonne, L, Nistico', R, Montoneri, E, Vaca Garcia, C, Nègre, M, and Institut National Polytechnique de Toulouse - INPT (FRANCE)

Subjects
CHIM/03 - CHIMICA GENERALE ED INORGANICA, Agronomie, 020209 energy, Biochimie, Biologie Moléculaire, 0211 other engineering and technologies, Zero waste, 02 engineering and technology, Post-harvest plants, Tomato, Maize, Thermopressing, Self-bonded fiberboards, chemistry.chemical_compound, 021105 building & construction, [SDV.IDA]Life Sciences [q-bio]/Food engineering, 0202 electrical engineering, electronic engineering, information engineering, Génie chimique, Organic matter, Hemicellulose, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Chemical composition, chemistry.chemical_classification, business.industry, Post-harvest plant, Biomécanique, Proximate, Biotechnology, Horticulture, Water soluble, chemistry, Agriculture, Environmental science, business, Sciences agricoles
Abstract

International audience; Post-harvest tomato plants were used to manufacture fireboards by thermopressing. Four plant materials were investigated: exhausted tomato plants ground to 5-10 mm (PHTr), tomato (PHT) and maize (PHM) plants ground to

Published
2017

9. Extruded Poly(ethylene–co–vinyl alcohol) Composite Films Containing Biopolymers Isolated from Municipal Biowaste

Author

Philippe Evon, Flavia Franzoso, Roberto Nisticò, Guadalupe Vaca-Medina, Michèle Negre, Carlos Vaca-Garcia, Matteo Francavilla, Enzo Montoneri, Giuliana Magnacca, Laurent Labonne, Università degli studi di Torino (UNITO), Chimie Agro-Industrielle (CAI), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National de la Recherche Agronomique (INRA), Biowaste Processing (ITALY), Università degli Studi di Foggia - University of Foggia, Regione Piemonte within Programma Operativo Regionale 'Competitivita regionale e occupazione' F.E.S.R., Nistico', R, Evon, P, Labonne, L, Vaca Medina, G, Montoneri, E, Francavilla, M, Vaca Garcia, C, Magnacca, G, Franzoso, F, Negre, M, Laboratoire de Chimie Agro-Industrielle (LCA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Toulouse, Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Università degli studi di Torino - UNITO (ITALY), Università degli Studi di Foggia - UNIFG (ITALY), Laboratoire de Chimie Agro-Industrielle - LCA (Toulouse, France), and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)

Subjects
Vinyl alcohol, Materials science, CHIM/03 - CHIMICA GENERALE ED INORGANICA, Matériaux, Biochimie, Composite number, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, biopolymers &amp, Biomaterials, chemistry.chemical_compound, Blend films, 11. Sustainability, Ultimate tensile strength, Copolymer, composite, Composite material, Solubility, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Composites, chemistry.chemical_classification, Extrusion, General Chemistry, Polymer, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Biomaterial, 6. Clean water, 0104 chemical sciences, Polymères, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM], blend film, Solvent, renewable polymer, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Chemical engineering, 13. Climate action, 0210 nano-technology, Biopolymers & renewable polymers
Abstract

International audience; Single-screw extrusion allows obtaining composite films containing poly(ethylene-co-vinyl alcohol), hereinafter EVOH, and water-soluble lignin-like biopolymers (SLP) isolated from the alkaline hydrolysate of two materials sampled from an urban waste treatment plant. During extrusion, a condensation reaction occurs between the EVOH and SLP. The products are heterogeneous. They contain a mix of EVOH-SLP copolymers with different composition and solubility properties. The films were characterized for tensile strength and water sorption properties. Young modulus and strain at break, respectively, were 2.8 GPa and 14% for neat EVOH vs. 2.1-0.9 GPa and 17–4% for the blends containing 2–15% SLP, with values decreasing upon increasing the % SLP. The blends were more hydrophilic than neat EVOH; their water sorption capacity was found to increase upon increasing the SLP content. Compared to previously reported similar blends obtained by twin-screw extrusion and solvent casting, the data for the single-screw extruded films allows discussing several aspects connected to the valorisation of blends obtained from fossil and biowaste sourced polymers.

Published
2016

10. Extruded versus solvent cast blends of poly(vinyl alcohol-co-ethylene) and biopolymers isolated from municipal biowaste

Author

Paola Persico, Matteo Francavilla, Enzo Montoneri, Antoine Rouilly, Philippe Evon, Flavia Franzoso, Carlos Vaca-Garcia, Raniero Mendichi, Roberto Nisticò, Franzoso, F, Vaca Garcia, C, Roully, A, Evon, P, Montoneri, E, Persico, P, Mendichi, R, Nistico', R, Francavilla, M, Biowaste Processing (ITALY), Consiglio Nazionale delle Ricerche - CNR (ITALY), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Università degli studi di Torino - UNITO (ITALY), Istituto per lo Studio delle Macromolecole - ISMAC-CNR (ITALY), Università degli Studi di Foggia - UNIFG (ITALY), Laboratoire de Chimie Agro-Industrielle - LCA (Toulouse, France), STAR*AgroEnergy, Universita di Torino, Chimie Agro-Industrielle (CAI), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National de la Recherche Agronomique (INRA), Biowaste Processing, Istituto per lo Studio delle Macromolecole, ISMAC, Consiglio Nazionale delle Ricerche [Roma] (CNR), University of Foggia, and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)

Subjects
Vinyl alcohol, CHIM/03 - CHIMICA GENERALE ED INORGANICA, Materials science, Polymers and Plastics, Matériaux, education, Size-exclusion chromatography, 02 engineering and technology, 010501 environmental sciences, 01 natural sciences, Hydrolysate, Biomaterials, Biopolymers and renewable polymers, chemistry.chemical_compound, biocompatibility, [SDV.IDA]Life Sciences [q-bio]/Food engineering, biomaterials, biopolymers and renewable polymers, blends, extrusion, 11. Sustainability, Materials Chemistry, Génie chimique, biopolymers and renewable polymer, Organic chemistry, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Static light scattering, Fourier transform infrared spectroscopy, Génie des procédés, 0105 earth and related environmental sciences, Extrusion, biomaterial, technology, industry, and agriculture, food and beverages, General Chemistry, 021001 nanoscience & nanotechnology, blend, 6. Clean water, Surfaces, Coatings and Films, Solvent, Blends, chemistry, Chemical engineering, 13. Climate action, Digestate, Biocompatibility, 0210 nano-technology
Abstract

International audience; Water-soluble biopolymers (SBO) were isolated from the alkaline hydrolysate of two materials sampled from an urban waste treatment plant; that is, an anaerobic fermentation digestate and a compost. The digestate biopolymers contained more lipophilic and aliphatic C, and less acidic functional groups than the compost biopolymers. The SBO were blended with poly (vinyl alcohol-co-ethylene), hereinafter EVOH. The blends were extruded and characterized by FTIR spectroscopy, size exclusion chromatography (SEC)-multi angle static light scattering (MALS) analysis, and for their thermal, rheological, and mechanical properties. The blends behavior depended on the type of SBO and its relative content. Evidence was obtained for a condensation reaction occurring between the EVOH and SBO. The best results were obtained with the blends containing up to 10% SBO isolated from the biowaste anaerobic digestate. Compared with the neat EVOH, these blends exhibited lower melt viscosity and no significant or great difference in mechanical properties. The results on the extrudates, compared with those previously obtained on the same blends obtained by solvent casting, indicate that the blends properties depend strongly also on the processing technology.

Published
2016

12. Liver cancer antiproliferative activity of a new nor-cucurbitacin from Mareya micrantha Müll. Arg.

Author

Toussaint-Douhoré GY, Soro Y, Ouédraogo N, Vaca-Garcia C, Koffi-Attioua B, and Carraz M

Subjects
Humans, Cucurbitacins, Molecular Structure, Triterpenes pharmacology, Triterpenes chemistry, Plants, Medicinal chemistry, Euphorbiaceae, Liver Neoplasms drug therapy
Abstract

Mareya micrantha Müll. Arg. (Euphorbiaceae) is a plant used in the Ivorian traditional medicinal system for various medical properties such as laxative, oxytocic, intestinal infectious diseases, malaria, etc. Six cucurbitacin derivatives (tetracyclic triterpenoids) are isolated from the leaves, stem barks or root barks of M. micrantha. Among these compounds, 29-nor-2β,15α,20β-trihydroxy-16α-acetyl-3,1,22-trioxo-cucurbita-4,23-diene (1) is a new nor-cucurbitacin isolated from the leaves; 29-nor-1,2,3,4,5,10-dehydro-3,15α,20β-trihydroxy-16α-acetyl-11,22-dioxo-cucurbita-23-ene 2-O-β-D-glucopyranoside (2) and 29-nor-2β,15α,20β-trihydroxy-16α-acetyl-3,11,22 trioxo-cucurbita-4,23-diene 2-O-β-D glucopyranoside (3) are new nor-cucurbitacins recently discovered by us in leaves and isolated again for this study while dihydro-epi-isocucurbitacin D (4), tetrahydro-cucurbitacin I (5) and cucurbitacin L (6) are known cucurbitacins but newly isolated from the stem barks and the root barks of M. micrantha. Their chemical structures are established according to spectral data (UV, IR, MS and 1 H, 13 C NMR). Their antiproliferative activity is explored in vitro on the chemo-resistant human hepatocarcinoma cell line Hep3B. Compound 1 showed a strong and selective antiproliferative activity against this cancer cell line (IC 50 value of 0.12 ± 0.05 μM) when compared to normal hepatocytes HepaRG., Competing Interests: Declaration of Competing Interest All authors declare having no competing interest., (Copyright © 2023. Published by Elsevier B.V.)

Published
2023
Full Text
View/download PDF

13. Nor-cucurbitacins from the leaves of Mareya micrantha (Benth.) Müll. Arg. (Euphorbiaceae).

Author

Douhoré GYT, Attioua KB, Soro Y, Kabran FA, Kablan LCA, Vedrenne M, Mathieu C, and Vaca-Garcia C

Subjects
Antioxidants chemistry, Cote d'Ivoire, Cucurbitacins isolation & purification, Molecular Structure, Phytochemicals chemistry, Phytochemicals isolation & purification, Plant Extracts chemistry, Plant Leaves chemistry, Plants, Medicinal chemistry, Cucurbitacins chemistry, Euphorbiaceae chemistry
Abstract

Mareya micrantha, an Ivoirian medicinal plant, was investigated for its chemical constituents and antioxidant properties. This study carried out on the hydroethanolic extract of the leaves led to three new nor-cucurbitacins named: 29-nor-1,2,3,4,5,10-dehydro-3,15α,20β-trihydroxy-16α-acetyl-11,22-dioxo-cucurbita-23-ene 2-O-β-D-glucopyranoside (1), 29-nor-2β,20β,25-trihydroxy-16α-acetyl-3,11,22-trioxo-cucurbita-4,23-diene (2) and 29-nor-2β,15α,20β-trihydroxy-16α-acetyl-3,11,22-trioxo-cucurbita-4,23-diene 2-O-β-D-glucopyranoside (3). The structures were established on the basis of spectral data (NMR, UV, MS and IR). The antioxidant properties evaluated by DPPH and CUPRAC methods gave the best activity with compound 1. The chemotaxonomic significance of the isolation of these compounds in Mareya micrantha, a species belonging to the Euphorbiaceae family, is discussed., Competing Interests: Declaration of Competing Interest None, (Copyright © 2020 Elsevier B.V. All rights reserved.)

Published
2020
Full Text
View/download PDF

14. Synthesis of new cellulose ethers using Suzuki-Miyaura reactions.

Author

Goncalves C, Favre C, Feuardant P, Klein S, Vaca-Garcia C, Cecutti C, Thiébaud-Roux S, and Vedrenne E

Abstract

Cellulose ethers are functionalized biopolymers that are industrially produced through drastic conditions employing gaseous reactants with a high risk of industrial accident. The cellulose ethers that are commercially available generally bear short carbon-chains. In this work, an alternative method using non-gaseous chemicals is proposed. It relies on the use of the Suzuki-Miyaura reaction employing mild, moisture- and air-stable conditions. Relatively innocuous reagents are used for this step, which allows the formation of a wide range of cellulose ethers bearing various functional groups with different chain-length., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Published
2015
Full Text
View/download PDF

15. Response surface methodology to optimise Accelerated Solvent Extraction of steviol glycosides from Stevia rebaudiana Bertoni leaves.

Author

Jentzer JB, Alignan M, Vaca-Garcia C, Rigal L, and Vilarem G

Subjects
Chromatography, High Pressure Liquid, Diterpenes, Kaurane chemistry, Europe, Glucosides chemistry, Models, Theoretical, Plant Extracts analysis, Plant Extracts chemistry, Reproducibility of Results, Solvents chemistry, Diterpenes, Kaurane isolation & purification, Glucosides isolation & purification, Plant Leaves chemistry, Stevia chemistry
Abstract

Following the approval of steviol glycosides as a food additive in Europe in December 2011, large-scale stevia cultivation will have to be developed within the EU. Thus there is a need to increase the efficiency of stevia evaluation through germplasm enhancement and agronomic improvement programs. To address the need for faster and reproducible sample throughput, conditions for automated extraction of dried stevia leaves using Accelerated Solvent Extraction were optimised. A response surface methodology was used to investigate the influence of three factors: extraction temperature, static time and cycle number on the stevioside and rebaudioside A extraction yields. The model showed that all the factors had an individual influence on the yield. Optimum extraction conditions were set at 100 °C, 4 min and 1 cycle, which yielded 91.8% ± 3.4% of total extractable steviol glycosides analysed. An additional optimisation was achieved by reducing the grind size of the leaves giving a final yield of 100.8% ± 3.3%., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Published
2015
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results