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.
2020
Martínez-Sanz, Marta; Larsson, Emanuel; Filli, Kalep B.; Loupiac, Camille; Assifaoui, Ali; López-Rubio, Amparo; Lopez-Sanchez, Patricia
Nano-/microstructure of extruded Spirulina/starch foams in relation to their textural properties Artículo de revista
En: Food Hydrocolloids, vol. 103, pp. 105697, 2020, ISSN: 0268-005X.
Resumen | Enlaces | BibTeX | Etiquetas: Gelatinization, Microalgae, Neutron tomography, SAXS, WAXS
@article{MARTINEZSANZ2020105697,
title = {Nano-/microstructure of extruded Spirulina/starch foams in relation to their textural properties},
author = {Marta Martínez-Sanz and Emanuel Larsson and Kalep B. Filli and Camille Loupiac and Ali Assifaoui and Amparo López-Rubio and Patricia Lopez-Sanchez},
url = {https://www.sciencedirect.com/science/article/pii/S0268005X19320156},
doi = {https://doi.org/10.1016/j.foodhyd.2020.105697},
issn = {0268-005X},
year = {2020},
date = {2020-01-01},
journal = {Food Hydrocolloids},
volume = {103},
pages = {105697},
abstract = {This work reports on an in-depth characterization of the nano- and microstructure of extruded starch foams loaded with the microalga Spirulina (1, 5 and 10 wt%), as well as the implications of Spirulina incorporation on the textural properties of the foams. Due to the gelatinization process occurring during extrusion, the crystalline and lamellar structures originally present in the starch granule were disrupted, resulting in very amorphous foams. Moreover, the crystalline structure of the fatty acids present in the raw microalga was lost during processing. The presence of Spirulina intracellular components induced the formation of more thermally-stable V-type crystallites through complexation with amylose, hence producing slightly more crystalline foams (XC~5–9%) than the pure extruded starch (XC ~3%). This affected the microstructure of the hybrid foams, which showed more densely packed and well-connected porous structures. Microstructural changes had an impact on the texture of the foams, which became harder with greater Spirulina loadings. The foams underwent very limited re-crystallization upon storage, which was further reduced by the presence of Spirulina. Interestingly, the free fatty acids from Spirulina re-crystallized and the resistant starch content in the 10% Spirulina foam increased, which could potentially be interesting from a nutritional perspective. These results show the potential of extrusion cooking to produce healthier snack foods and highlight the suitability of advanced characterization tools such as neutron tomography and small angle X-ray scattering to investigate food structure.},
keywords = {Gelatinization, Microalgae, Neutron tomography, SAXS, WAXS},
pubstate = {published},
tppubtype = {article}
}
This work reports on an in-depth characterization of the nano- and microstructure of extruded starch foams loaded with the microalga Spirulina (1, 5 and 10 wt%), as well as the implications of Spirulina incorporation on the textural properties of the foams. Due to the gelatinization process occurring during extrusion, the crystalline and lamellar structures originally present in the starch granule were disrupted, resulting in very amorphous foams. Moreover, the crystalline structure of the fatty acids present in the raw microalga was lost during processing. The presence of Spirulina intracellular components induced the formation of more thermally-stable V-type crystallites through complexation with amylose, hence producing slightly more crystalline foams (XC~5–9%) than the pure extruded starch (XC ~3%). This affected the microstructure of the hybrid foams, which showed more densely packed and well-connected porous structures. Microstructural changes had an impact on the texture of the foams, which became harder with greater Spirulina loadings. The foams underwent very limited re-crystallization upon storage, which was further reduced by the presence of Spirulina. Interestingly, the free fatty acids from Spirulina re-crystallized and the resistant starch content in the 10% Spirulina foam increased, which could potentially be interesting from a nutritional perspective. These results show the potential of extrusion cooking to produce healthier snack foods and highlight the suitability of advanced characterization tools such as neutron tomography and small angle X-ray scattering to investigate food structure.
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.
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