Structural and functional properties of alginate obtained by means of high hydrostatic pressure-assisted extraction

[EN] The effects of the high hydrostatic pressure (HPP) pre-treatment on the alginate extraction were seen to greatly depend on the recalcitrant nature of two algae species. Alginates were deeply characterized in terms of composition, structure (HPAEC-PAD, FTIR, NMR, SEC-MALS), functional and techno...

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Detalles Bibliográficos
Autores: Bojorges-Gutierrez, Hylenne, Martínez-Abad, Antonio, Marta Martínez-Sanz, Vilaplana Domingo, Francisco Javier, López-Rubio, Amparo, Fabra Rovira, Maria José
Tipo de recurso: artículo
Fecha de publicación:2023
País:España
Institución:Universitat Politècnica de València (UPV)
Repositorio:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Idioma:inglés
OAI Identifier:oai:riunet.upv.es:10251/208611
Acceso en línea:https://riunet.upv.es/handle/10251/208611
Access Level:acceso abierto
Palabra clave:Brown seaweed
HPP
M/G ratio
Molecular weight
Nanostructure
Polysaccharide extraction
Descripción
Sumario:[EN] The effects of the high hydrostatic pressure (HPP) pre-treatment on the alginate extraction were seen to greatly depend on the recalcitrant nature of two algae species. Alginates were deeply characterized in terms of composition, structure (HPAEC-PAD, FTIR, NMR, SEC-MALS), functional and technological properties. The pre-treatment significantly increased the alginate yield in the less recalcitrant A. nodosum (AHP) also favoring the extraction of sulphated fucoidan/fucan structures and polyphenols. Although the molecular weight was significantly lower in AHP samples, neither the M/G ratio nor the M and G sequences were modified. In contrast, a lower increase in alginate extraction yield was observed for the more recalcitrant S. latissima after the HPP pre-treatment (SHP), but it significantly affected the M/G values of the resulting extract. The gelling properties of the alginate extracts were also explored by external gelation in CaCl2 solutions. The mechanical strength and nanostructure of the hydrogel beads prepared were determined using compression tests, synchrotron small angle X-ray scattering (SAXS), and cryo-scanning electron microscopy (Cryo-SEM). Interestingly, the application of HPP significantly improved the gel strength of SHP, in agreement with the lower M/G values and the stiffer rod-like conformation obtained for these samples.