Publicaciones

@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}

}