2022
Cebrián-Lloret, Vera; Metz, Mandy; Martínez-Abad, Antonio; Knutsen, Svein Halvor; Ballance, Simon; López-Rubio, Amparo; Martínez-Sanz, Marta
Valorization of alginate-extracted seaweed biomass for the development of cellulose-based packaging films Artículo de revista
En: Algal Research, vol. 61, pp. 102576, 2022, ISSN: 2211-9264.
Resumen | Enlaces | BibTeX | Etiquetas: Biopolymers, Cellulose, Packaging, Seaweed, Valorization
@article{CEBRIANLLORET2022102576,
title = {Valorization of alginate-extracted seaweed biomass for the development of cellulose-based packaging films},
author = {Vera Cebrián-Lloret and Mandy Metz and Antonio Martínez-Abad and Svein Halvor Knutsen and Simon Ballance and Amparo López-Rubio and Marta Martínez-Sanz},
url = {https://www.sciencedirect.com/science/article/pii/S2211926421003957},
doi = {https://doi.org/10.1016/j.algal.2021.102576},
issn = {2211-9264},
year = {2022},
date = {2022-01-01},
journal = {Algal Research},
volume = {61},
pages = {102576},
abstract = {Seaweed residues from Alaria esculenta, Saccharina latissima and Ascophyllum nodosum after alginate extraction have been valorized to produce cellulose-based fractions with different purification degrees. The residues were mainly composed of carbohydrates (35–57%) and proteins (12–37%), Alaria and Saccharina being richer in cellulose and Ascophyllum richer in fucoidan. The lower cellulose content in the latter made it unsuitable for the extraction of cellulosic fractions. Self-supporting films were obtained from the cellulosic fractions from Saccharina and Alaria residues. While the higher cellulose purity films presented more desirable characteristics in terms of mechanical properties (with elastic moduli of ca. 5–7 GPa and elongation values of ca. 3–5%) and visual appearance, the presence of non-cellulosic components in the films from less purified fractions reduced their water sensitivity and promoted greater water barrier (with water permeability values of ca. 4–6 kg·m/s·m2·Pa). These results point towards the potential of a simple alkaline extraction to generate cellulose-based films from seaweed residuals with the best compromise between functional properties and economical and environmental efficiency.},
keywords = {Biopolymers, Cellulose, Packaging, Seaweed, Valorization},
pubstate = {published},
tppubtype = {article}
}
Seaweed residues from Alaria esculenta, Saccharina latissima and Ascophyllum nodosum after alginate extraction have been valorized to produce cellulose-based fractions with different purification degrees. The residues were mainly composed of carbohydrates (35–57%) and proteins (12–37%), Alaria and Saccharina being richer in cellulose and Ascophyllum richer in fucoidan. The lower cellulose content in the latter made it unsuitable for the extraction of cellulosic fractions. Self-supporting films were obtained from the cellulosic fractions from Saccharina and Alaria residues. While the higher cellulose purity films presented more desirable characteristics in terms of mechanical properties (with elastic moduli of ca. 5–7 GPa and elongation values of ca. 3–5%) and visual appearance, the presence of non-cellulosic components in the films from less purified fractions reduced their water sensitivity and promoted greater water barrier (with water permeability values of ca. 4–6 kg·m/s·m2·Pa). These results point towards the potential of a simple alkaline extraction to generate cellulose-based films from seaweed residuals with the best compromise between functional properties and economical and environmental efficiency.
2021
Gómez-Mascaraque, Laura G.; Martínez-Sanz, Marta; Martínez-López, Rosalia; Martínez-Abad, Antonio; Panikuttira, Bhavya; López-Rubio, Amparo; Tuohy, Maria G.; Hogan, Sean A.; Brodkorb, André
Characterization and gelling properties of a bioactive extract from Ascophyllum nodosum obtained using a chemical-free approach Artículo de revista
En: Current Research in Food Science, vol. 4, pp. 354-364, 2021, ISSN: 2665-9271.
Resumen | Enlaces | BibTeX | Etiquetas: Algae, Hydrogel, Polysaccharide, SAXS, Seaweed
@article{GOMEZMASCARAQUE2021354,
title = {Characterization and gelling properties of a bioactive extract from Ascophyllum nodosum obtained using a chemical-free approach},
author = {Laura G. Gómez-Mascaraque and Marta Martínez-Sanz and Rosalia Martínez-López and Antonio Martínez-Abad and Bhavya Panikuttira and Amparo López-Rubio and Maria G. Tuohy and Sean A. Hogan and André Brodkorb},
url = {https://www.sciencedirect.com/science/article/pii/S266592712100037X},
doi = {https://doi.org/10.1016/j.crfs.2021.05.005},
issn = {2665-9271},
year = {2021},
date = {2021-01-01},
journal = {Current Research in Food Science},
volume = {4},
pages = {354-364},
abstract = {The bioactivity and gelling properties of a carbohydrate-rich algal extract obtained from locally harvested Ascophyllum nodosum seaweed using a chemical-free approach were investigated for its potential interest in food applications. Physicochemical characterisation and compositional analysis of the extract, using FTIR, biochemical methods and monosaccharide analysis, confirmed the presence of alginates and fucoidans, although the main polysaccharide present in it was laminarin. Significant amounts of phenolic compounds (~9 mg phloroglucinol/100 mg sample) were also detected. As a result, the extract exhibited good antioxidant activity. It also showed promising prebiotic potential, promoting the growth of beneficial Lactobacillus sp. and Bifidobacteria sp. when compared with commercial prebiotics, but not that of pathogenic bacteria such as E. coli or P. aeruginosa. The gelling properties of the raw extract were explored to optimize hydrogel bead formation by external gelation in CaCl2 solutions. This was enhanced at neutral to alkaline pHs and high extract and CaCl2 concentrations. The mechanical strength, nano- and microstructure of the hydrogel beads prepared under optimised conditions were determined using compression tests, synchrotron small- and wide-angle X-ray scattering (SAXS/WAXS) and scanning electron microscopy (SEM). It was concluded that the raw algal extract at neutral pH had potential for use as a gelling agent, although further enrichment with alginate improved the mechanical properties of the obtained gels. The advantages and disadvantages of applying the non-purified algal extract in comparison with purified carbohydrates are discussed.},
keywords = {Algae, Hydrogel, Polysaccharide, SAXS, Seaweed},
pubstate = {published},
tppubtype = {article}
}
The bioactivity and gelling properties of a carbohydrate-rich algal extract obtained from locally harvested Ascophyllum nodosum seaweed using a chemical-free approach were investigated for its potential interest in food applications. Physicochemical characterisation and compositional analysis of the extract, using FTIR, biochemical methods and monosaccharide analysis, confirmed the presence of alginates and fucoidans, although the main polysaccharide present in it was laminarin. Significant amounts of phenolic compounds (~9 mg phloroglucinol/100 mg sample) were also detected. As a result, the extract exhibited good antioxidant activity. It also showed promising prebiotic potential, promoting the growth of beneficial Lactobacillus sp. and Bifidobacteria sp. when compared with commercial prebiotics, but not that of pathogenic bacteria such as E. coli or P. aeruginosa. The gelling properties of the raw extract were explored to optimize hydrogel bead formation by external gelation in CaCl2 solutions. This was enhanced at neutral to alkaline pHs and high extract and CaCl2 concentrations. The mechanical strength, nano- and microstructure of the hydrogel beads prepared under optimised conditions were determined using compression tests, synchrotron small- and wide-angle X-ray scattering (SAXS/WAXS) and scanning electron microscopy (SEM). It was concluded that the raw algal extract at neutral pH had potential for use as a gelling agent, although further enrichment with alginate improved the mechanical properties of the obtained gels. The advantages and disadvantages of applying the non-purified algal extract in comparison with purified carbohydrates are discussed.
Martínez-Sanz, Marta; Gomez-Barrio, Laura Pilar; Zhao, Ming; Tiwari, Brijesh; Knutsen, Svein Halvor; Ballance, Simon; Zobel, Hanne Kristine; Nilsson, Anna Ekman; Krewer, Christoffer; Östergren, Karin; López-Rubio, Amparo
Alternative protocols for the production of more sustainable agar-based extracts from Gelidium sesquipedale Artículo de revista
En: Algal Research, vol. 55, pp. 102254, 2021, ISSN: 2211-9264.
Resumen | Enlaces | BibTeX | Etiquetas: Antioxidant capacity, Microwaves, Phycocolloids, Seaweed, Ultrasounds
@article{MARTINEZSANZ2021102254,
title = {Alternative protocols for the production of more sustainable agar-based extracts from Gelidium sesquipedale},
author = {Marta Martínez-Sanz and Laura Pilar Gomez-Barrio and Ming Zhao and Brijesh Tiwari and Svein Halvor Knutsen and Simon Ballance and Hanne Kristine Zobel and Anna Ekman Nilsson and Christoffer Krewer and Karin Östergren and Amparo López-Rubio},
url = {https://www.sciencedirect.com/science/article/pii/S2211926421000734},
doi = {https://doi.org/10.1016/j.algal.2021.102254},
issn = {2211-9264},
year = {2021},
date = {2021-01-01},
journal = {Algal Research},
volume = {55},
pages = {102254},
abstract = {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.},
keywords = {Antioxidant capacity, Microwaves, Phycocolloids, Seaweed, Ultrasounds},
pubstate = {published},
tppubtype = {article}
}
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.
2020
Benito-González, Isaac; López-Rubio, Amparo; Gómez-Mascaraque, Laura G.; Martínez-Sanz, Marta
PLA coating improves the performance of renewable adsorbent pads based on cellulosic aerogels from aquatic waste biomass Artículo de revista
En: Chemical Engineering Journal, vol. 390, pp. 124607, 2020, ISSN: 1385-8947.
Resumen | Enlaces | BibTeX | Etiquetas: Biopolymers, Microstructure, Oil sorption, Porous materials, Seaweed
@article{BENITOGONZALEZ2020124607,
title = {PLA coating improves the performance of renewable adsorbent pads based on cellulosic aerogels from aquatic waste biomass},
author = {Isaac Benito-González and Amparo López-Rubio and Laura G. Gómez-Mascaraque and Marta Martínez-Sanz},
url = {https://www.sciencedirect.com/science/article/pii/S1385894720305982},
doi = {https://doi.org/10.1016/j.cej.2020.124607},
issn = {1385-8947},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
journal = {Chemical Engineering Journal},
volume = {390},
pages = {124607},
abstract = {Lightweight, hydrophobic, adsorbent pads based on aerogels from different cellulosic and nanocellulosic fractions extracted from Posidonia oceanica waste biomass were developed by a simple freeze-drying and PLA dipping method. The pure (nano)cellulosic aerogels presented highly porous structures, capable of adsorbing large amounts of oil (up to ~34 g oil/g aerogel); however, they lost their integrity when soaked in water. The incorporation of PLA hydrophobized the aerogels and improved significantly their mechanical performance (up to 10-fold increase in the compression stress). The most porous aerogel structures, obtained with the lowest (nano)cellulosic concentrations and with the less purified fractions, incorporated greater amounts of PLA upon dipping, which was mostly distributed filling in the pores. All the PLA-coated (nano)cellulosic aerogels presented a hydrophobic behaviour, with contact angles of 95–130° and selectively adsorbing greater amounts of oil (5.9–9.2 g oil/g aerogel) than water (2.8–6.7 g H2O/g aerogel). These materials present a great potential as adsorbent pads for oil spill cleaning and food packaging applications.},
keywords = {Biopolymers, Microstructure, Oil sorption, Porous materials, Seaweed},
pubstate = {published},
tppubtype = {article}
}
Lightweight, hydrophobic, adsorbent pads based on aerogels from different cellulosic and nanocellulosic fractions extracted from Posidonia oceanica waste biomass were developed by a simple freeze-drying and PLA dipping method. The pure (nano)cellulosic aerogels presented highly porous structures, capable of adsorbing large amounts of oil (up to ~34 g oil/g aerogel); however, they lost their integrity when soaked in water. The incorporation of PLA hydrophobized the aerogels and improved significantly their mechanical performance (up to 10-fold increase in the compression stress). The most porous aerogel structures, obtained with the lowest (nano)cellulosic concentrations and with the less purified fractions, incorporated greater amounts of PLA upon dipping, which was mostly distributed filling in the pores. All the PLA-coated (nano)cellulosic aerogels presented a hydrophobic behaviour, with contact angles of 95–130° and selectively adsorbing greater amounts of oil (5.9–9.2 g oil/g aerogel) than water (2.8–6.7 g H2O/g aerogel). These materials present a great potential as adsorbent pads for oil spill cleaning and food packaging applications.
Fontes-Candia, Cynthia; Ström, Anna; Gómez-Mascaraque, Laura G.; López-Rubio, Amparo; Martínez-Sanz, Marta
Understanding nanostructural differences in hydrogels from commercial carrageenans: Combined small angle X-ray scattering and rheological studies Artículo de revista
En: Algal Research, vol. 47, pp. 101882, 2020, ISSN: 2211-9264.
Resumen | Enlaces | BibTeX | Etiquetas: Food texture, Gelation, Polysaccharide, Scattering, Seaweed
@article{FONTESCANDIA2020101882,
title = {Understanding nanostructural differences in hydrogels from commercial carrageenans: Combined small angle X-ray scattering and rheological studies},
author = {Cynthia Fontes-Candia and Anna Ström and Laura G. Gómez-Mascaraque and Amparo López-Rubio and Marta Martínez-Sanz},
url = {https://www.sciencedirect.com/science/article/pii/S2211926419309932},
doi = {https://doi.org/10.1016/j.algal.2020.101882},
issn = {2211-9264},
year = {2020},
date = {2020-01-01},
journal = {Algal Research},
volume = {47},
pages = {101882},
abstract = {Hydrogels from commercial carrageenans (κ-C, ι-C, λ↑-C (high viscosity) and λ↓-C (low viscosity)) were prepared with and without the addition of salts (KCl and CaCl2). FT-IR and 1H NMR characterization evidenced that while the κ-C and ι-C grades were relatively pure carrageenans, the two λ-C grades were λ-, κ-, θ- and μ-carrageenan hybrids. The effect of carrageenan and salt concentration on the hydrogel strength were evaluated through a response surface design and a detailed structural characterization was carried out by small angle X-ray scattering (SAXS) and rheology. The low amount of sulphate substitution in κ-C enabled intramolecular association, giving rise to strong hydrogels, even in the absence of salts. On the other hand, ι-C, λ↑-C and λ↓-C produced much weaker hydrogels and required the addition of salts to induce intramolecular association by ionic cross-linking. SAXS results suggested the formation of similar structures of double helices in κ-C and ι-C with the addition of salts; however, distinct network structures were attained. In the case of κ-C, a Gauss-Lorentz gel model was suitable to describe the hydrogel structure and the addition of K+ promoted the formation of more ordered and densely packed structures. On the other hand, larger but weaker aggregates, with marked periodicity, were observed in ι-C, with Ca2+ inducing the formation of more densely packed networks. The complex composition of the λ-C grades gave rise to more heterogeneous branched network structures, properly described by a correlation length model, where the gelation mechanism was mostly governed by the κ-carrageenan component.},
keywords = {Food texture, Gelation, Polysaccharide, Scattering, Seaweed},
pubstate = {published},
tppubtype = {article}
}
Hydrogels from commercial carrageenans (κ-C, ι-C, λ↑-C (high viscosity) and λ↓-C (low viscosity)) were prepared with and without the addition of salts (KCl and CaCl2). FT-IR and 1H NMR characterization evidenced that while the κ-C and ι-C grades were relatively pure carrageenans, the two λ-C grades were λ-, κ-, θ- and μ-carrageenan hybrids. The effect of carrageenan and salt concentration on the hydrogel strength were evaluated through a response surface design and a detailed structural characterization was carried out by small angle X-ray scattering (SAXS) and rheology. The low amount of sulphate substitution in κ-C enabled intramolecular association, giving rise to strong hydrogels, even in the absence of salts. On the other hand, ι-C, λ↑-C and λ↓-C produced much weaker hydrogels and required the addition of salts to induce intramolecular association by ionic cross-linking. SAXS results suggested the formation of similar structures of double helices in κ-C and ι-C with the addition of salts; however, distinct network structures were attained. In the case of κ-C, a Gauss-Lorentz gel model was suitable to describe the hydrogel structure and the addition of K+ promoted the formation of more ordered and densely packed structures. On the other hand, larger but weaker aggregates, with marked periodicity, were observed in ι-C, with Ca2+ inducing the formation of more densely packed networks. The complex composition of the λ-C grades gave rise to more heterogeneous branched network structures, properly described by a correlation length model, where the gelation mechanism was mostly governed by the κ-carrageenan component.
Fontes-Candia, Cynthia; Ström, Anna; Lopez-Sanchez, Patricia; López-Rubio, Amparo; Martínez-Sanz, Marta
Rheological and structural characterization of carrageenan emulsion gels Artículo de revista
En: Algal Research, vol. 47, pp. 101873, 2020, ISSN: 2211-9264.
Resumen | Enlaces | BibTeX | Etiquetas: Fat replacement, Gelation, Polysaccharide, Scattering, Seaweed
@article{FONTESCANDIA2020101873,
title = {Rheological and structural characterization of carrageenan emulsion gels},
author = {Cynthia Fontes-Candia and Anna Ström and Patricia Lopez-Sanchez and Amparo López-Rubio and Marta Martínez-Sanz},
url = {https://www.sciencedirect.com/science/article/pii/S2211926419312482},
doi = {https://doi.org/10.1016/j.algal.2020.101873},
issn = {2211-9264},
year = {2020},
date = {2020-01-01},
journal = {Algal Research},
volume = {47},
pages = {101873},
abstract = {Carrageenan emulsion gels containing sunflower oil were prepared using three different commercial carrageenan grades (κ-C, ι-C and λ-C). The effect of the carrageenan and salt content, as well as the oil:water ratio, on the emulsion gel strength was evaluated through a response surface methodology. Moreover, the rheological properties and the micro- and nanostructure from the stronger emulsion gel formulations were investigated and compared to their analogous hydrogel formulations. Interestingly, emulsion gels formed stronger and more thermally stable networks than the hydrogels, being this effect more evident in ι-C and λ-C. The results indicate that this was mainly due to a polysaccharide concentration effect, as no evidence of interactions between the carrageenan and the oil phase was found. Consequently, the rheological behaviour of the emulsion gels was mostly determined by the type of carrageenan. The association of carrageenan molecular chains was favoured in κ-C and λ-C (due to the presence of κ-carrageenan in the latter) and promoted by the addition of KCl. In contrast, a lower degree of chain association, mostly driven by ionic cross-linking, took place in ι-C. These results evidence the relevance of the gelation mechanism on the properties of emulsion gels and provide the basis for the design of these systems for targeted applications within the food industry.},
keywords = {Fat replacement, Gelation, Polysaccharide, Scattering, Seaweed},
pubstate = {published},
tppubtype = {article}
}
Carrageenan emulsion gels containing sunflower oil were prepared using three different commercial carrageenan grades (κ-C, ι-C and λ-C). The effect of the carrageenan and salt content, as well as the oil:water ratio, on the emulsion gel strength was evaluated through a response surface methodology. Moreover, the rheological properties and the micro- and nanostructure from the stronger emulsion gel formulations were investigated and compared to their analogous hydrogel formulations. Interestingly, emulsion gels formed stronger and more thermally stable networks than the hydrogels, being this effect more evident in ι-C and λ-C. The results indicate that this was mainly due to a polysaccharide concentration effect, as no evidence of interactions between the carrageenan and the oil phase was found. Consequently, the rheological behaviour of the emulsion gels was mostly determined by the type of carrageenan. The association of carrageenan molecular chains was favoured in κ-C and λ-C (due to the presence of κ-carrageenan in the latter) and promoted by the addition of KCl. In contrast, a lower degree of chain association, mostly driven by ionic cross-linking, took place in ι-C. These results evidence the relevance of the gelation mechanism on the properties of emulsion gels and provide the basis for the design of these systems for targeted applications within the food industry.
Martínez-Sanz, Marta; Cebrián-Lloret, Vera; Mazarro-Ruiz, Jesús; López-Rubio, Amparo
Improved performance of less purified cellulosic films obtained from agar waste biomass Artículo de revista
En: Carbohydrate Polymers, vol. 233, pp. 115887, 2020, ISSN: 0144-8617.
Resumen | Enlaces | BibTeX | Etiquetas: Agar, Biopolymers, Cellulose, Packaging, Seaweed, Valorization
@article{MARTINEZSANZ2020115887,
title = {Improved performance of less purified cellulosic films obtained from agar waste biomass},
author = {Marta Martínez-Sanz and Vera Cebrián-Lloret and Jesús Mazarro-Ruiz and Amparo López-Rubio},
url = {https://www.sciencedirect.com/science/article/pii/S0144861720300618},
doi = {https://doi.org/10.1016/j.carbpol.2020.115887},
issn = {0144-8617},
year = {2020},
date = {2020-01-01},
journal = {Carbohydrate Polymers},
volume = {233},
pages = {115887},
abstract = {The residues generated after the extraction of agar from Gelidium sesquipedale by means of a hot-water treatment, with (NaOH+HW residue) and without (HW residue) an alkali pre-treatment have been valorized to produce high performance cellulosic films. Both residues were mainly composed of structural carbohydrates (in particular, agar), ashes and lipids. The residual agar could only be completely removed by applying a two-step process based on bleaching and alkaline treatments. The application of the alkaline pre-treatment for the extraction of agar did not significantly affect the properties of the films produced from the extracted fractions, hence making the HW residue more sustainable and economically viable. The agar remaining in the less purified fractions had a positive effect on the performance of the films, improving their transparency, mechanical properties and water vapour barrier, outperforming benchmark biopolymers; in addition, these materials presented antioxidant capacity inhibiting the degradation of β-carotene.},
keywords = {Agar, Biopolymers, Cellulose, Packaging, Seaweed, Valorization},
pubstate = {published},
tppubtype = {article}
}
The residues generated after the extraction of agar from Gelidium sesquipedale by means of a hot-water treatment, with (NaOH+HW residue) and without (HW residue) an alkali pre-treatment have been valorized to produce high performance cellulosic films. Both residues were mainly composed of structural carbohydrates (in particular, agar), ashes and lipids. The residual agar could only be completely removed by applying a two-step process based on bleaching and alkaline treatments. The application of the alkaline pre-treatment for the extraction of agar did not significantly affect the properties of the films produced from the extracted fractions, hence making the HW residue more sustainable and economically viable. The agar remaining in the less purified fractions had a positive effect on the performance of the films, improving their transparency, mechanical properties and water vapour barrier, outperforming benchmark biopolymers; in addition, these materials presented antioxidant capacity inhibiting the degradation of β-carotene.
Martínez-Sanz, Marta; Ström, Anna; Lopez-Sanchez, Patricia; Knutsen, Svein Halvor; Ballance, Simon; Zobel, Hanne Kristine; Sokolova, Anna; Gilbert, Elliot Paul; López-Rubio, Amparo
Advanced structural characterisation of agar-based hydrogels: Rheological and small angle scattering studies Artículo de revista
En: Carbohydrate Polymers, vol. 236, pp. 115655, 2020, ISSN: 0144-8617.
Resumen | Enlaces | BibTeX | Etiquetas: Molecular weight, Rheology, SANS, SAXS, Seaweed
@article{MARTINEZSANZ2020115655,
title = {Advanced structural characterisation of agar-based hydrogels: Rheological and small angle scattering studies},
author = {Marta Martínez-Sanz and Anna Ström and Patricia Lopez-Sanchez and Svein Halvor Knutsen and Simon Ballance and Hanne Kristine Zobel and Anna Sokolova and Elliot Paul Gilbert and Amparo López-Rubio},
url = {https://www.sciencedirect.com/science/article/pii/S0144861719313232},
doi = {https://doi.org/10.1016/j.carbpol.2019.115655},
issn = {0144-8617},
year = {2020},
date = {2020-01-01},
journal = {Carbohydrate Polymers},
volume = {236},
pages = {115655},
abstract = {Agar-based extracts from Gelidium sesquipedale were generated by heat and combined heat-sonication, with and without the application of alkali pre-treatment. Pre-treatment yielded extracts with greater agar contents; however, it produced partial degradation of the agar, reducing its molecular weight. Sonication produced extracts with lower agar contents and decreased molecular weights. A gelation mechanism is proposed based on the rheological and small angle scattering characterization of the extracts. The formation of strong hydrogels upon cooling was caused by the association of agarose chains into double helices and bundles, the sizes of which depended on the agar purity and molecular weight. These different arrangements at the molecular scale consequently affected the mechanical performance of the obtained hydrogels. Heating of the hydrogels produced a gradual disruption of the bundles; weaker or smaller bundles were formed upon subsequent cooling, suggesting that the process was not completely reversible.},
keywords = {Molecular weight, Rheology, SANS, SAXS, Seaweed},
pubstate = {published},
tppubtype = {article}
}
Agar-based extracts from Gelidium sesquipedale were generated by heat and combined heat-sonication, with and without the application of alkali pre-treatment. Pre-treatment yielded extracts with greater agar contents; however, it produced partial degradation of the agar, reducing its molecular weight. Sonication produced extracts with lower agar contents and decreased molecular weights. A gelation mechanism is proposed based on the rheological and small angle scattering characterization of the extracts. The formation of strong hydrogels upon cooling was caused by the association of agarose chains into double helices and bundles, the sizes of which depended on the agar purity and molecular weight. These different arrangements at the molecular scale consequently affected the mechanical performance of the obtained hydrogels. Heating of the hydrogels produced a gradual disruption of the bundles; weaker or smaller bundles were formed upon subsequent cooling, suggesting that the process was not completely reversible.
© GRUPO DE PROTEÍNAS ALIMENTARIAS - 