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Al Jawad H, Rabiller-Baudry M, Loulergue P, Bejjani C, Lejeune A, Mawlawi H, Nasser G, Taha S. On the impact of ethanol on the rejection and transfer mechanism during ultrafiltration of a charged macromolecule in water/ethanol. Environ Technol 2020; 41:1950-1979. [PMID: 30481129 DOI: 10.1080/09593330.2018.1552724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/30/2018] [Indexed: 06/09/2023]
Abstract
Ultrafiltration (UF) is a sustainable membrane separation technique. It could be useful for the concentration/purification of bio-sourced molecules that are extracted either by pure ethanol or by water/ethanol mixtures. Nevertheless, the process optimization requires an in-depth understanding of the transfer mechanisms of solute through membranes, especially for charged solutes, that are nowadays not sufficiently documented. Previous studies achieved in aqueous media have shown that the rejection of charged solutes by an UF membrane involves at least three mechanisms: convection, diffusion and electrostatic interactions. The present study aims at a systematic analysis of the transfer mechanisms of a model protein (lysozyme) in water/ethanol mixtures (100/0-70/30 v/v) during UF by a zirconia inorganic membrane. The influence of the pH varying in the 4-9 range and of the ionic strength (I) is also discussed. The ionic strength I can be adjusted by addition of an indifferent electrolyte (NaCl) only aiming at the screening of the electrostatic interactions or by addition of a selectively adsorbed electrolyte(KH2PO4) that is able to change the isoelectric pH of the protein and thus to modulate the electrostatic interactions in a different way when compared to NaCl. Of course, both salts have an impact on the protein rejection in UF. The results are analysed using the CDE model previously developed in our group to explain the behaviour of a single protein during UF in water and accounting for convection, diffusion and electrophoretic migration. The applicability of the CDE model in water/ethanol mixtures up to 70/30 v/v is finally shown.
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Affiliation(s)
- H Al Jawad
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), Rennes, France
- Université Libanaise, Laboratoire de Biotechnologie Appliquée: Biomolécules, Biothérapies et Bioprocédés du Centre AZM pour la Recherche en Biotechnologie et ses Applications, Beyrouth, Lebanon
| | - M Rabiller-Baudry
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), Rennes, France
| | - P Loulergue
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), Rennes, France
| | - C Bejjani
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), Rennes, France
- Faculté d'Agronomie et Médecine Vétérinaire, département Sciences et Technologies Agroalimentaires, Université Libanaise, Dekwaneh, Lebanon
| | - A Lejeune
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), Rennes, France
| | - H Mawlawi
- Université Libanaise, Laboratoire de Biotechnologie Appliquée: Biomolécules, Biothérapies et Bioprocédés du Centre AZM pour la Recherche en Biotechnologie et ses Applications, Beyrouth, Lebanon
| | - G Nasser
- Faculté d'Agronomie et Médecine Vétérinaire, département Sciences et Technologies Agroalimentaires, Université Libanaise, Dekwaneh, Lebanon
| | - S Taha
- Université Libanaise, Laboratoire de Biotechnologie Appliquée: Biomolécules, Biothérapies et Bioprocédés du Centre AZM pour la Recherche en Biotechnologie et ses Applications, Beyrouth, Lebanon
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Vernhet A, Carrillo S, Rattier A, Verbaere A, Cheynier V, Nguela JM. Fate of Anthocyanins and Proanthocyanidins during the Alcoholic Fermentation of Thermovinified Red Musts by Different Saccharomyces cerevisiae Strains. J Agric Food Chem 2020; 68:3615-3625. [PMID: 32067460 DOI: 10.1021/acs.jafc.0c00413] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
UV-visible spectrophotometry, size exclusion chromatography, and UHPLC-QqQ-MS were combined to evaluate the respective impacts of chemical changes and adsorption by yeasts on both proanthocyanidins (PA) and anthocyanins during the fermentation of a thermovinified red must by four yeast strains. Results evidenced a sharp decrease in anthocyanins (∼45%) and color intensity (∼50%), along with the formation of pyranoanthocyanins and flavanol-anthocyanin dimers related to yeast metabolism. However, the latter only accounted for 10% of anthocyanin losses. Comparison of spectrophotometry and phloroglucinolysis data underlined the involvement of PAs in chemical changes, related to yeast metabolites but also to direct reactions. Color losses during fermentation in this case study were mostly related to the formation of colorless compounds and to a decrease of copigmentation. Adsorption represented only a small proportion of pigment losses (∼5%) but a major part of those corresponding to total oligomeric/polymeric species, which were specifically involved. Only small differences could be evidenced between the four studied strains.
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Affiliation(s)
- Aude Vernhet
- SPO, University Montpellier, INRAE, Montpellier SupAgro, 34060 Montpellier, France
| | - Stéphanie Carrillo
- SPO, University Montpellier, INRAE, Montpellier SupAgro, 34060 Montpellier, France
| | - Anaïs Rattier
- SPO, University Montpellier, INRAE, Montpellier SupAgro, 34060 Montpellier, France
| | - Arnaud Verbaere
- SPO, University Montpellier, INRAE, Montpellier SupAgro, 34060 Montpellier, France
| | - Véronique Cheynier
- SPO, University Montpellier, INRAE, Montpellier SupAgro, 34060 Montpellier, France
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