Production of unpurified agar-based extracts from red seaweed Gelidium sesquipedale by means of simplified extraction protocols

This work reports on the production and characterization of agar-based extracts from the seaweed Gelidium sesquipedale by means of simple protocols based on hot water and sonication treatments. The combination of sonication with the hot water treatment reduced 4-fold the extraction time without sign...

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Detalhes bibliográficos
Autores: Martínez Sanz, Marta, Gómez-Mascaraque, Laura G., Ballester Frutos, Ana Rosa, Martínez Abad, Antonio, Brodkorb, André, López-Rubio, Amparo
Formato: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2019
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/177603
Acesso em linha:http://hdl.handle.net/10261/177603
Access Level:acceso abierto
Palavra-chave:Red seaweed
Gels
Sulphated polysaccharides
Ultrasound-assisted extraction
Food hydrocolloids
Descrição
Resumo:This work reports on the production and characterization of agar-based extracts from the seaweed Gelidium sesquipedale by means of simple protocols based on hot water and sonication treatments. The combination of sonication with the hot water treatment reduced 4-fold the extraction time without significantly affecting the extraction yield (ca. 10–12%) and the extracts' properties. Apart from agar, the extracts contained proteins, polyphenols and minerals, which conferred them high antioxidant capacity and led to the production of brownish softer gels. The application of an alkali pre-treatment yielded almost pure agars, with higher molecular weights and crystallinities than commercial agar, resulting in stiffer gels. However, the partial digestion of agar by the alkali led to low extraction yields (ca. 2–3%). These results show the efficiency of the combined heat and sonication method to generate cost-effective agar-based extracts with potential applications within the food industry.