![]() Is non-gelling as the lack of the 1C 4 3,6-anhydro-linkĮnables the galactose residues to revert to their 4 C 1 conformation, which does not allow the initial double helix formation Helices to form junction zones in soft elastic gels with good freeze-thaw Has less specific ionic binding, but increased ionic strength allows Gels may be softened (and are generally regarded to be synergistically The coil-double helix transition precedes a K +-inducedĪggregation of the helices. κ- and ι-carrageenansįorm thermoreversible gels on cooling in the presence of suitableįorms a firm, clear, if brittle, gel with poor freeze-thaw stability. FunctionalityĬarrageenans are used mainly for thickening, suspending, and gelling. Units but still forming double-helical junction zones. Note that the gelling hydrocolloid agar is produced from the same family of seaweeds, the significant differenceīeing the presence of L- rather than D-3,6-anhydro-α-galactopyranose An increase in the affinity of D 2O molecules for each other relative to polysaccharide water linkages probably explains this. This has been attributed to an increase in the number of double-helix aggregates rather than the fraction of helix formed, which differs little between the two solvents. Κ-Carrageenan forms stronger gels in D 2O rather than H 2O. Will reduce the extent of helix formation as the unbridged α-linked galactose residues may Incomplete formation of 1C 4 3,6-anhydro-links The strongest gels of κ-carrageenan are formed with K + rather than Li +, Na +, Mg 2+, Ca 2+, or Sr 2+. ![]() Such phase separation aids helix formation but subsequently supportsĪggregating linkages between the helices so forming the junction You cannot use Na +, although Na + does take part in an aggregation process to form weak gelsĭue to phase separation ). With gel-inducing and gel-strengthening K + or Ca 2+ cations, respectively. Involves helix formation on cooling from a hot solution together Higher concentrations, wind around each other to form double-helical All carrageenans are highly flexible molecules that, at C 1 OC 4H 4 or C 1 OC 3C 3) have been determined for λ-, μ- and ν-carrageenans.
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