Please use this identifier to cite or link to this item:
https://hdl.handle.net/10316/14461
DC Field | Value | Language |
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dc.contributor.author | Van de Velde, Fred | - |
dc.contributor.author | Antipova, Anna S. | - |
dc.contributor.author | Rollema, Harry S. | - |
dc.contributor.author | Burova, Tatiana V. | - |
dc.contributor.author | Grinberg, Nataliya V. | - |
dc.contributor.author | Pereira, Leonel | - |
dc.contributor.author | Gilsenan, Paula M. | - |
dc.contributor.author | Tromp, R. Hans | - |
dc.contributor.author | Rudolph, Brian | - |
dc.contributor.author | Grinberg, Valerij Ya. | - |
dc.date.accessioned | 2011-02-02T13:34:39Z | - |
dc.date.available | 2011-02-02T13:34:39Z | - |
dc.date.issued | 2005-05-02 | - |
dc.identifier.citation | VAN DE VELDE, Fred [et al.] - The structure of j/i-hybrid carrageenans II. Coil–helix transition as a function of chain composition. "Carbohydrate Research". ISSN 0008-6215. Vol. 340 nº 6 (2005) 1113-1129 | - |
dc.identifier.issn | 0008-6215 | - |
dc.identifier.uri | https://hdl.handle.net/10316/14461 | - |
dc.description.abstract | This paper describes the effect of the k/i-ratio on the physical properties of k/i-hybrid carrageenans (synonyms: kappa-2, k-2, weak kappa, weak gelling kappa). To this end, a series of k/i-hybrid carrageenans ranging from almost homopolymeric k-carrageenan (98 mol% k-units) to almost homopolymeric-carrageenan (99 mol% i-units) have been extracted from selected species of marine red algae (Rhodophyta). The k/i-ratio of these k/i-hybrids was determined by NMR spectroscopy. Their rheological properties were determined by small deformation oscillatory rheology. The gel strength (storage modulus, G0) of the j/i-hybrids decreases with decreasing j-content. On the other hand, the gelation temperature of the k-rich k/i-hybrids is independent of their composition. This allows one to control the gel strength independent of the gelation or melting temperature. The conformational order–disorder transition of the k/i-hybrids was studied using optical rotation and high-sensitivity differential scanning calorimetry. High-sensitivity DSC showed that the total transition enthalpy of the k/i-hybrids goes through a minimum at 60 mol% k-units, whereas for the mixture of j- and i-carrageenan, the total transition enthalpy is a linear function of the composition. With respect to the ordering capability, the k/i-hybrid carrageenans seem to behave as random block copolymers with length sequence distributions truncated from the side of the small lengths. Intrinsic thermodynamic properties (e.g., transition temperature and enthalpy) of k- and i-sequences in these copolymers are close to those of their parent homopolymers. The critical sequence length for k-sequences is 2-fold of that for i-sequences. | por |
dc.language.iso | eng | por |
dc.rights | openAccess | por |
dc.subject | Carrageenan | por |
dc.subject | Kappa/iota-Hybrids | por |
dc.subject | Polysaccharides | - |
dc.subject | Coil-to-helix transition | - |
dc.subject | Structural analysis | - |
dc.subject | Differential scanning calorimetry | - |
dc.title | The structure of j/i-hybrid carrageenans II. Coil–helix transition as a function of chain composition | por |
dc.type | article | por |
degois.publication.firstPage | 1113 | por |
degois.publication.lastPage | 1129 | por |
degois.publication.issue | 6 | - |
degois.publication.title | Carbohydrate Research | por |
dc.peerreviewed | Yes | por |
dc.identifier.doi | 10.1016/j.carres.2005.02.015 | - |
degois.publication.volume | 340 | por |
uc.controloAutoridade | Sim | - |
item.fulltext | Com Texto completo | - |
item.openairecristype | http://purl.org/coar/resource_type/c_18cf | - |
item.grantfulltext | open | - |
item.languageiso639-1 | en | - |
item.openairetype | article | - |
item.cerifentitytype | Publications | - |
crisitem.author.researchunit | MARE - Marine and Environmental Sciences Centre | - |
crisitem.author.orcid | 0000-0002-6819-0619 | - |
Appears in Collections: | FCTUC Ciências da Vida - Artigos em Revistas Internacionais |
Files in This Item:
File | Description | Size | Format | |
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The structure of j/i-hybrid carrageenans II.pdf | 427.89 kB | Adobe PDF | View/Open |
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