Alternative protocols for the production of more sustainable agar-based extracts from Gelidium sesquipedale

Agar-based extracts from Gelidium sesquipedale were obtained by applying a conventional hot water treatment and alternative ultrasound- and microwave-assisted methods, with and without the application of an alkaline pre-treatment. The alkaline pre-treatment produced refined extracts with higher puri...

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Detalhes bibliográficos
Autores: Martínez Sanz, Marta, Gomez-Barrio, Laura Pilar, Zhao, Ming, Knutseni, Brijesh Tiwar, Halvor, Svein, Ballance, Simon, Zobel, Hanne Kristine, Ekman Nilsson, Anna, Krewer, Christoffer, Östergren, Karin, López-Rubio, Amparo
Tipo de documento: artigo
Estado:Versión aceptada para publicación
Data de publicação:2021
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositório:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/244849
Acesso em linha:http://hdl.handle.net/10261/244849
Access Level:Acceso aberto
Palavra-chave:Seaweed
Gelidium sesquipedale
Ultrasounds
Microwaves
Phycocolloids
Antioxidant capacity
Descrição
Resumo:Agar-based extracts from Gelidium sesquipedale were obtained by applying a conventional hot water treatment and alternative ultrasound- and microwave-assisted methods, with and without the application of an alkaline pre-treatment. The alkaline pre-treatment produced refined extracts with higher purity; however, extraction yields increased from 2–5% to 7–19% by omitting this step. In particular, the ultrasound-assisted extraction allowed reducing 4-fold the extraction time, while keeping constant or even increasing the yield (up to 19% for the 1 h extraction) with respect to the conventional protocol. Interestingly, the presence of proteins and polyphenols conferred the semi-refined extracts a relatively high antioxidant capacity (19–24 μmol TE/g extract). The refined extract produced by the standard protocol formed the strongest hydrogels (>1000 g/cm2). On the other hand, the semi-refined extracts produced by the alternative protocols formed slightly stronger hydrogels (337–438 g/cm2) than the refined counterparts (224–311 g/cm2), due to their greater molecular weights of the former ones. LCA assessment showed lower global warming potential for the semi-refined extracts, especially the ultrasound-assisted extraction, hence highlighting the potential of this method to produce more sustainable agar-based extracts for food-related applications.