Pedro Adão1, Maria da Luz Calado1, Luis G. Alves2, Mafalda Guedes3,4, Raul Bernardino5-7, Susana Bernardino5, Maria Jorge Campos5, Maria M. Gil5
1 MARE – Marine and Environmental Sciences Centre, Polytechnic of Leiria, 2520–614 Peniche, Portugal
2 Centro de Química Estrutural – Institute of Molecular Sciences, Associação do Instituto Superior Técnico para a Investigação e Desenvolvimento, Av. Rovisco País 1, 1049-003 Lisboa, Portugal
3 CDP2T and Department of Mechanical Engineering, Escola Superior de Tecnologia de Setúbal, Instituto Politécnico de Setúbal, 2910-761 Setúbal, Portugal
4 CeFEMA, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
5 MARE – Marine and Environmental Sciences Centre / ARNET – Aquatic Research Network, ESTM, Polytechnic of Leiria, 2520-641 Peniche, Portugal
6 LSRE-LCM – Laboratory of Separation and Reaction Engineering – Laboratory of Catalysis and Materials, School of Tourism and Maritime Technology (ESTM), Polytechnic of Leiria, 2520–614 Peniche, Portugal
7 ALiCE – Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
Marine macroalgae are important renewable feedstock for important polysaccharides such as agarose, carrageenans and alginates, which, in turn, are widely used as thickeners and stabilisers in the food industry. Algal polysaccharides such as iota-carrageenan and sodium alginate are particularly interesting due to their ability to form insoluble gels in the presence of calcium ions. This presents an opportunity to contribute to the minimisation of the environmental impact caused by the waste residue generated by the stone processing industry [1,2], where the processed stone sludge can be used as a source of calcium ions for the hardening of iota-carrageenan/alginate composite films. With this in mind, we developed iota-carrageenan/alginate composite films hardened with processed carbonate rock sludge as potential replacements for single-use petroleum-based plastics. While the structural, chemical and antimicrobial properties of the developed films are currently under analysis, the films prepared with a carrageenan/alginate proportion of 75/25, in conjunction with D-sorbitol (plasticizer) contents ranging from 50 to 100 %, present a texture and flexibility similar to regenerated cellulose when dry. As such, these films may have a potential application as food packaging with low environmental impact.
Acknowledgements: This work was financially supported by LA/P/0045/2020 (ALiCE), UIDB/50020/2020 and UIDP/50020/2020 (LSRE-LCM), funded by national funds through FCT/MCTES (PIDDAC), by FCT – Fundação para a Ciência e a Tecnologia, I.P., within the scope of the project MARE (UIDB/04292/2020 and UIDP/04292/2020) and through the project INOVMINERAL 4.0 – Tecnologias Avançadas e Software para os recursos Minerais, project number 46083, cofinanced by FEDER – Fundo Europeu de Desenvolvimento Regional, in the scope of the Programa Portugal 2020, through COMPETE 2020 – Programa Operacional. This study also had the support of national funds through Fundação para a Ciência e Tecnologia (FCT), under the project LA/P/0069/2020 granted to the Associate Laboratory ARNET. Mafalda Guedes acknowledges FCT under contract UIDB/04540/2020, through CeFEMA. Luis G. Alves acknowledges Fundação para a Ciência e a Tecnologia, Portugal for funding (UIDP/00100/2020, UIDB/00100/2020, LA/P/0056/2020).
References:
[1] Careddu, N.; Dino, G. A. Environmental Earth Sciences 2016, 75, 1075. https://doi.org/10.1007/s12665-016-5865-1.
[2] Yurdakul, M. Journal of Cleaner Production 2020, 276, 123339. https://doi.org/10.1016/j.jclepro.2020.123339.