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

COSENZA, V. A.; NAVARRO, D. A.; FISSORE, E. N.; ROJAS, A. M.; STORTZ, C. A.

CARBOHYDRATE POLYMERS

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2014 vol. 102 p. 780 - 789

0144-8617

This work reports a chemical and rheological study of the carrageenans from Hypnea musciformis, a redseaweed commercially known for its production of -carrageenan. The polysaccharides were extractedwith water both at room temperature and at 90◦C: the yield of the latter was about six times larger thanthe former. Fractionation with KCl yielded a large proportion (50?67%) of a precipitate with 0.125 M ofthis salt for both extracts, with characteristics of a nearly pure -carrageenan, as determined by methyla-tion analysis and NMR spectroscopy. Smaller amounts of fractions precipitating at higher concentrationsshowed a basic -carrageenan structure, but included some -carrageenan diads. The KCl-soluble polysac-charides showed a larger complexity, containing d- and l-galactans or d/l-hybrids. Some differences inthe rheological properties of these carrageenans have been found. Although all KCl-precipitating polysac-charides form true gels at 10◦C in presence of KCl, those extracted with hot water form stronger gelsthan those extracted at room temperature. Both purified -carrageenans show lower gelling and meltingtemperature than the whole polysaccharides from which they were originated.