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Alginates

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Jack Legrand – 1st expert on this subject based on the ideXlab platform

  • a new process for extracting Alginates from laminaria digitata reactive extrusion
    Food and Bioprocess Technology, 2008
    Co-Authors: Peggy Vauchel, Raymond Kaas, Abdellah Arhaliass, Regis Baron, Jack Legrand

    Abstract:

    Alginates are natural polysaccharides that are extracted from brown seaweeds and widely used for their rheological properties. The main step in the extraction protocol used in the alginate industry is that of alkaline extraction. A batch process is used for this step, which is time-, water-, and reactant-consuming. The possibility of extracting by reactive extrusion was investigated. The reactive extrusion process appeared to be more efficient than the batch process for the alkaline extraction of Alginates from Laminaria digitata in several key ways: Time demand is reduced from about an hour to only few minutes, water and reactant requirements are divided by more than a factor 2, extraction yield is 15% higher (relative enhancement), and the rheological properties of the product were all enhanced. Hence, reactive extrusion could be an interesting alternative process for the alginate industry to produce high rheological properties Alginates.

  • A new process for the extraction of Alginates from Laminaria digitata : reactive extrusion
    Food and Bioprocess Technology, 2008
    Co-Authors: Peggy Vauchel, Raymond Kaas, Abdellah Arhaliass, Regis Baron, Jack Legrand

    Abstract:

    Alginates are natural polysaccharides that are extracted from brown seaweeds and widely used for their rheological properties. The main step in the extraction protocol used in the alginate industry is that of alkaline extraction. A batch process is used for this step, which is time-, water-, and reactant-consuming. The possibility of extracting by reactive extrusion was investigated. The reactive extrusion process appeared to be more efficient than the batch process for the alkaline extraction of Alginates from Laminaria digitata in several key ways: Time demand is reduced from about an hour to only few minutes, water and reactant requirements are divided by more than a factor 2, extraction yield is 15% higher (relative enhancement), and the rheological properties of the product were all enhanced. Hence, reactive extrusion could be an interesting alternative process for the alginate industry to produce high rheological properties Alginates.

  • Decrease in dynamic viscosity and average molecular weight of alginate from Laminaria digitata during alkaline extraction
    Journal of Phycology, 2008
    Co-Authors: Peggy Vauchel, Jack Legrand, Raymond Kaas, Abdellah Arhaliass, Regis Baron

    Abstract:

    Alginates are natural polysaccharides that are extracted from brown seaweeds and widely used for their rheological properties. The central step in the extraction protocol used in the alginate industry is the alkaline extraction, which requires several hours. In this study, a significant decrease in alginate dynamic viscosity was observed after 2 h of alkaline treatment. Intrinsic viscosity and average molecular weight of Alginates from alkaline extractions 1–4 h in duration were determined, indicating depolymerization of Alginates: average molecular weight decreased significantly during the extraction, falling by a factor of 5 between 1 and 4 h of extraction. These results suggested that reducing extraction time could enable preserving the rheological properties of the extracted Alginates.

Kijung Paeng – 2nd expert on this subject based on the ideXlab platform

  • effect of calcium ion cross linker concentration on porosity surface morphology and thermal behavior of calcium Alginates prepared from algae undaria pinnatifida
    Carbohydrate Polymers, 2010
    Co-Authors: Tara Sankar Pathak, Kijung Paeng

    Abstract:

    Abstract Alginic acid and metal (sodium) Alginates was prepared from fresh algae using hot extraction method. Calcium Alginates are also prepared from sodium alginate by varying calcium ion (calcium chloride) concentrations. FTIR spectra indicate that alginic acid is converted into metal alginate. Surface morphology as well as total intrusion volume, porosity (%) and pore size distribution changes by changing calcium ion (cross-linker) concentrations. Thermal degradation of calcium Alginates showed a stepwise weight loss during thermal sweep, indicating different types of reactions during degradation. Calcium alginate (Calg0.6) prepared at low calcium ion concentration is least stable whereas at highest calcium ion concentration, the alginate sample (Calg20) is most stable at final degradation temperature (800 °C). Kinetic analysis was performed to fit with TGA data, where the entire degradation process has been considered as four consecutive 1st order reactions.

  • effect of cross linker and cross linker concentration on porosity surface morphology and thermal behavior of metal Alginates prepared from algae undaria pinnatifida
    Carbohydrate Polymers, 2009
    Co-Authors: Tara Sankar Pathak, Daejin Baek, Kijung Paeng

    Abstract:

    Abstract Alginic acid and metal Alginates are prepared from fresh algae using extraction method. FTIR spectra indicate that alginic acid is converted into metal alginate. Asymmetric stretching of free carboxyl group of zinc alginate at 1596 cm −1 is shifted to 1582 cm −1 in cadmium alginate, due to the change of charge density, radius and atomic weight of the cation. Surface morphology changes by changing the cross-linker and cross-linker concentration at same magnification. Total intrusion volume, porosity (%) and pore size distribution also changes by changing cross-linker and cross-linker concentration. Thermal degradation results reveals that zinc and cadmium Alginates started decomposing at 100 °C, but rapid degradation started around 300 °C and showed a stepwise weight loss during thermal sweep, indicating different types of reactions during degradation. Kinetic analysis was performed to fit with TGA data, where the entire degradation process has been considered as two or three consecutive 1st order reactions.

Peggy Vauchel – 3rd expert on this subject based on the ideXlab platform

  • a new process for extracting Alginates from laminaria digitata reactive extrusion
    Food and Bioprocess Technology, 2008
    Co-Authors: Peggy Vauchel, Raymond Kaas, Abdellah Arhaliass, Regis Baron, Jack Legrand

    Abstract:

    Alginates are natural polysaccharides that are extracted from brown seaweeds and widely used for their rheological properties. The main step in the extraction protocol used in the alginate industry is that of alkaline extraction. A batch process is used for this step, which is time-, water-, and reactant-consuming. The possibility of extracting by reactive extrusion was investigated. The reactive extrusion process appeared to be more efficient than the batch process for the alkaline extraction of Alginates from Laminaria digitata in several key ways: Time demand is reduced from about an hour to only few minutes, water and reactant requirements are divided by more than a factor 2, extraction yield is 15% higher (relative enhancement), and the rheological properties of the product were all enhanced. Hence, reactive extrusion could be an interesting alternative process for the alginate industry to produce high rheological properties Alginates.

  • A new process for the extraction of Alginates from Laminaria digitata : reactive extrusion
    Food and Bioprocess Technology, 2008
    Co-Authors: Peggy Vauchel, Raymond Kaas, Abdellah Arhaliass, Regis Baron, Jack Legrand

    Abstract:

    Alginates are natural polysaccharides that are extracted from brown seaweeds and widely used for their rheological properties. The main step in the extraction protocol used in the alginate industry is that of alkaline extraction. A batch process is used for this step, which is time-, water-, and reactant-consuming. The possibility of extracting by reactive extrusion was investigated. The reactive extrusion process appeared to be more efficient than the batch process for the alkaline extraction of Alginates from Laminaria digitata in several key ways: Time demand is reduced from about an hour to only few minutes, water and reactant requirements are divided by more than a factor 2, extraction yield is 15% higher (relative enhancement), and the rheological properties of the product were all enhanced. Hence, reactive extrusion could be an interesting alternative process for the alginate industry to produce high rheological properties Alginates.

  • Decrease in dynamic viscosity and average molecular weight of alginate from Laminaria digitata during alkaline extraction
    Journal of Phycology, 2008
    Co-Authors: Peggy Vauchel, Jack Legrand, Raymond Kaas, Abdellah Arhaliass, Regis Baron

    Abstract:

    Alginates are natural polysaccharides that are extracted from brown seaweeds and widely used for their rheological properties. The central step in the extraction protocol used in the alginate industry is the alkaline extraction, which requires several hours. In this study, a significant decrease in alginate dynamic viscosity was observed after 2 h of alkaline treatment. Intrinsic viscosity and average molecular weight of Alginates from alkaline extractions 1–4 h in duration were determined, indicating depolymerization of Alginates: average molecular weight decreased significantly during the extraction, falling by a factor of 5 between 1 and 4 h of extraction. These results suggested that reducing extraction time could enable preserving the rheological properties of the extracted Alginates.