Chemical and rheological characterization of the carrageenans from Hypnea musciformis (Wulfen) Lamoroux.

Autor: Cosenza VA; Departamento de Química Orgánica-CIHIDECAR, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina., Navarro DA; Departamento de Química Orgánica-CIHIDECAR, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina., Fissore EN; Departamento de Industrias, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina., Rojas AM; Departamento de Industrias, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina., Stortz CA; Departamento de Química Orgánica-CIHIDECAR, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina. Electronic address: stortz@qo.fcen.uba.ar.
Jazyk: angličtina
Zdroj: Carbohydrate polymers [Carbohydr Polym] 2014 Feb 15; Vol. 102, pp. 780-9. Date of Electronic Publication: 2013 Nov 06.
DOI: 10.1016/j.carbpol.2013.10.090
Abstrakt: This work reports a chemical and rheological study of the carrageenans from Hypnea musciformis, a red seaweed commercially known for its production of κ-carrageenan. The polysaccharides were extracted with water both at room temperature and at 90 °C: the yield of the latter was about six times larger than the former. Fractionation with KCl yielded a large proportion (50-67%) of a precipitate with 0.125 M of this salt for both extracts, with characteristics of a nearly pure κ-carrageenan, as determined by methylation analysis and NMR spectroscopy. Smaller amounts of fractions precipitating at higher concentrations showed a basic κ-carrageenan structure, but included some ι-carrageenan diads. The KCl-soluble polysaccharides showed a larger complexity, containing d- and l-galactans or d/l-hybrids. Some differences in the rheological properties of these carrageenans have been found. Although all KCl-precipitating polysaccharides form true gels at 10 °C in presence of KCl, those extracted with hot water form stronger gels than those extracted at room temperature. Both purified κ-carrageenans show lower gelling and melting temperature than the whole polysaccharides from which they were originated.
(Copyright © 2013 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE